I am using Vivo V11 & while browsing through the installed app section I came about one called Facebook App manager. I don't have any social media apps installed on my phone. There is no option to delete it. Both Force stop & uninstall buttons are greyed out. Under permission it showed access provided to storage which I have disabled now.
Feb 4, 2019, 12:36:45 PM via Website
Feb 4, 2019 12:36:45 PM via Website
V2x
I was afraid of that!
See I have both of those apps disabled.
Nevertheless I keep seeing a file for Facebook appearing in my Internal Storage! I have deleted this file many times, and it keeps coming back!
Google and Facebook must be doing this through Play Services!
Unfortunately I'm fresh out of ideas on how to stop it!
If you start messing around with Play Services, you could screw up your Android operating system!
Jan 24, 2019, 11:59:58 AM via Website
Jan 24, 2019 11:59:58 AM via Website
I have a s7 that app was factory installed in my phone also, the only thing you can do is disable it!
Unless you root your phone!
Any issues if I root my phone? Not a big fan of anything related to FB.
Jan 24, 2019, 11:18:30 PM via Website
Jan 24, 2019 11:18:30 PM via Website
V2x
Before you root your phone, make sure that you back up all your apps in a file on a different computer !
Just in case you delete a app and it causes problems, you can always go to your back up and reinstall that app!
(This is very important)
If you go into settings under all apps you might find 2 Facebook apps.
One will be called Facebook
The other is Facebook apps manager.
You will probably want to root them both.
One other thing, if your phone is still under warranty you could void out your warranty by rooting the phone!
Bye the way , I'm not a fan of Facebook either!
— modified on Jan 24, 2019, 11:41:46 PM
Lindsay mcdaniel
If you go into settings under all apps you might find 2 Facebook apps.
One will be called Facebook
The other is Facebook apps manager.
You will probably want to root them both.One other thing, if your phone is still under warranty you could void out your warranty by rooting the phone!
Bye the way , I'm not a fan of Facebook either!
The phone is just a week old, so a whole year of warranty left. 
I don't have any social media apps installed. FB app was preinstalled so I removed that.
According to customer care it is a harmless app. Doubt if anything FB related is harmless.
Worst case scenario if I root the phone & mess it up, Can I reset it to factory default again?
Jan 25, 2019, 12:07:49 PM via Website
Jan 25, 2019 12:07:49 PM via Website
Just a heads up!
When you root your phone, you are taking the app completely out of your hard drive!
A Factory Default (reset) will not bring them back! That's why you create the back up file!
If those apps come back after you root them let me know!
Found the solution by accident.
Did a factory reset & deleted the FB app immediately. When I checked the app list neither was there.
My guess is that this gets installed once you update the app. All good now. 
Thanks for the suggestions.
Jan 26, 2019, 1:21:03 PM via Website
Jan 26, 2019 1:21:03 PM via Website
Just 2 things you should check on!
Internal storage! See if there is a Facebook file there, and delete it!
Google settings, in connected apps.
See if Facebook is there and deleted it!
Bye the way! You did this just in time!
I just read in the tech news that Facebook is starting to integrate WhatsApp and Instagram into thier app.
This should be a big mess!
Glad you got it figured out!
Take care!
— modified on Jan 26, 2019, 1:34:47 PM
Looks like they were never uninstalled. Activated the developer mode & found two FB apps (FB app installer & FB app manager). Cannot uninstall or deactivate them. You deactivate them & once you reopen the background apps screens you find both the apps activated again.
Feb 4, 2019, 12:36:45 PM via Website
Feb 4, 2019 12:36:45 PM via Website
V2x
I was afraid of that!
See I have both of those apps disabled.
Nevertheless I keep seeing a file for Facebook appearing in my Internal Storage! I have deleted this file many times, and it keeps coming back!
Google and Facebook must be doing this through Play Services!
Unfortunately I'm fresh out of ideas on how to stop it!
If you start messing around with Play Services, you could screw up your Android operating system!
They really make it hard for people to trust them. 
Feb 4, 2019, 1:31:43 PM via Website
Feb 4, 2019 1:31:43 PM via Website
V2x
They really make it hard for people to trust them.
It's all about money!
And when it comes to money I have learned not to trust ANYONE!
Disabling is pretty much useless. Never ever buy any device that has Facebook preinstalled on it!
Facebook and Google both can not be trusted.
Before busting a phone go to a demo model and check under Apps to see if any Facebook apps were already installed by manufacturer if so that means Facebook paid them to make sure that they can not be uninstalled which means that even if disabled they will continue to steal info
Feb 4, 2019, 11:13:15 PM via Website
Feb 4, 2019 11:13:15 PM via Website
Mark Crystal
Disabling is pretty much useless. Never ever buy any device that has Facebook preinstalled on it!
Facebook and Google both can not be trusted.Before busting a phone go to a demo model and check under Apps to see if any Facebook apps were already installed by manufacturer if so that means Facebook paid them to make sure that they can not be uninstalled which means that even if disabled they will continue to steal info
Good advice Mark!
But, if Facebook is paying Google to do this, I'll bet that all newer Android phones
have those apps in them!
Then there's iPhones, it's a well known fact that Apple and Facebook are very friendly with each other.
If you find a new smartphone that doesn't
Have those apps in them let me know what phone it is!
When it comes to Android, I am still a novice. Just my second android phone. The first one (Moto G5) was stock android. Once Windows stopped the first choice was shifting to iPhone but they make it really hard for you to buy the phone. Not going to spend 70k for a phone that will get obsolete in a few years.
Windows was a lot simpler...
Vijay
When it comes to Android, I am still a novice. Just my second android phone. The first one (Moto G5) was stock android. Once Windows stopped the first choice was shifting to iPhone but they make it really hard for you to buy the phone. Not going to spend 70k for a phone that will get obsolete in a few years.
Windows was a lot simpler...
Hey!
If you can help me in this regard.
I have deactivated my messenger rather then deleting the whole facebook Account.
I followed the random guide and followed its steps. I have deactivated it but still I got a push notification if someone texts me.
Can you please tell me what should I do and how to stop that, because I have already deactivated it.
Maybe the steps that I followed was not complete?
Please guide me.
Sorry I forgot to mention that I followed the PureVPN's guide to deactivate messenger. More or less the steps are same on all guides.
What should I do now?
Notification can be disabled in settings.
Go to Settings, then Apps & notifications. Once there select the app then select app notifications & then turn it off. Some apps give the option to turn off select notifications like Uber, where you can keep the travel related notifications but deactivate promotional ones. If you don't want any notifications, just turn it off completely.