If your phone is out of contract you could contact AT&T and ask them to factory unlock it for you..
Or you could unlock using gevey sim..
There has to be a reason why they don't want to unlock it. Your brother, as an owner of that AT&T account should call them. They should unlock it, provided that account is "clean".well my brother gave it to me and he owes att so they dont want to unlock it... so any legit website that can do it? i've seen a few that charge from 20-50 but dont know if they are legit.