How to unblock my pin? sim lock on family mobile

[AC Question]

My tmobile samsung galaxy s3 has locked up. The message on the screen says that my pin blocked and my sim card needs unlocked. i cannot contact my service provider because my phone will not get off that screen

 

[Rukbat]

Walk into a TMobile store - they can help you if they have the phone in their hands. (Bring picture ID to prove that it's your account.)