My carrier is T-mobile.
I love the Galaxy S4 active due to the waterproof feature, but it's made only for AT&T.
I bought the phone from someone, but I need to unlock it to work with T-Mobile, but AT&T will not unlock it.
I have seen many sites out there, but they seem sketchy. Has anyone had any success with any of them?

If it helps, I have the Galaxy S4 active i537