A complicated problem

I was trying to switch between my mother's cell phone and mine, because I wanted to play Pokemon Go on her phone while she still could use WhatsApp in my phone without losing any contacts. Here's what happened:

First, I misused the option "Change number" because I didn't know what it does. So, after I switched the SIM cards, I got my mom's phone (with my number in it) and attempted to switch numbers and did the same with my phone (with my mom's number in it). So, naturally, now my number was listed as my mom's, because that's what the option "Change number" does (now I know that). So now, as it was, my number was in all her groups and her number was in all my groups. Also, my number had her photo and etc.

After that, I realized I messed up and tried to undo everything. I switched the SIM cards back and tried to use the same option to change the numbers back. But, apparently, you can't do that with both phones at the same time. So here's how it is now:
At first, I thought neither me or her was in any groups. But, I asked for a friend to send a message in one of the groups I'm usually in. I was added back instantly when he sent it. It doesn't even seem like I was out of it, even though it showed I was no longer a participant. That's cool, at that point I thought everything had worked perfectly and whenever someone sent a message on any group, I would be added back and things would go back to normal (I assumed the same would happen with her number and phone). BUT, after that, I received another message in a group I wasn't a participant of. It was one of my mom's groups. Since someone sent a message in that group, "my mom" was added back, because for some reason, I was still also listed as her number.
Now, I'm on both my groups and her groups. About her phone: she's on neither and, also, I can't verify her number (at least for the next seven hours). She's not even listed. It's like she doesn't have a whatsapp.