I need help with getting FaceTime to work on my iPhone 4s 5.1.1 I have searched several pages of google and tried just about everything i've come across and nothing fixes it. I have a Pay as you GO AT&T micro sim (official) that activates FaceTime and iMessage. However, I want to use the phone Unlocked with what I currently have which is Simple Mobile. Once I switch out the sim cards, FaceTime goes back to "waiting for activation". It also has the at&t phone number greyed out, even though I have the Simple Mobile sim card inserted. Is there a fix for this? Any help is appreciated.