iPhone unlock request approved, but SIM card not supported
I need help unlocking my father's iPhone 6 Plus. I submitted an unlock request through the online portal on 6/13, and it was approved the same day. However, following the non-AT&T SIM card instructions does not complete the unlock. He receives the message that the SIM card is not supported, and he needs to contact the carrier to unlock the phone. He has not done an iTunes backup and restore, as he does not have an AT&T SIM card.
From reading other customers' similar problems, it sounds like something is stuck in the communication between AT&T and Apple's servers. Others have mentioned solving the issue by having AT&T customer service "push through" the unlock to Apple. I am unable to find a way to contact anyone directly about this.