So I paid for an IMEI unlock for my iPhone 4S. Worked fine on 5.1.1. When I restored to 6.1.2, iTunes said "Congratualtions, your iPhone is unlocked:. However, inserting my Rogers SIM into my AT&T iPhone is giving me a "no service" error. According to the online IMEI checkers, the phone is indeed unlociked. Any ideas?