There is a way to unlock your phone yourself. There are many How to videos on you tube explaining how to do it.
And all you need is a home PC to do it.
However some cell phone carriers enter programming to the hard drive that will forbid any other carrier from activating it.
And you cannot erease that programming.
So you may be able to unlock your phone
But no other cellphone carrier will be able to activate it.
My best suggestion is; next time you buy a new device, don't buy it from a cell phone store. Go to a electronics store and purchase a unlocked phone like I did!
Now if I want to change carriers, all I have to do is remove the old sims card and have the new phone company insert thier sims card and activate it!
And unlocked phones cost less, and they don't have a bunch of bloatware apps preinstalled!