Okay... I'm hoping someone tech savvy can help me with this issue. I had an account with T-mobile, but because they are charging me for a bill I do not owe I went to Straight Talk. Now my phone will not use the Straight Talk SIM card because the phone account is cancelled and the phone itself is locked. I'm wondering if there is a way to unlock my phone or if I can root it or something. Any help or suggestions would be greatly appreciated. It's a T-Mobile Samsung Galaxy s4.