Q: Unlocking an AT&T when your not an AT&T customer

I recently bought off eBay a iPhone 5 it was supposed to be unlocked, so when it arrived (I should say I'm currently on an extended stay in Greece and my son brought my purchase to me from the states) I bought a SIM card from the main carrier in Greece.

Placed the SIM card in the iPhone and get a message that is attached

So contact AT&T, not an easy task if your not a customer.. but did go through the procedure to 'unlock the phone' get approved yet it would not unlock, finally contact them through FaceBook, and hear that it is under review.. but they emailed it was approved.. Now it has been 8 days, had my wife call them from the states to also first be told it was unlocked, then under approval, again.. Now today I get a message from AT&T

Hello Louie. I just confirmed we've processed the first unlock steps on our side. You now need to plug your phone into your computer with the phone's manufacture's software up and running and perform a factory restore as new with this software in conjunction with your phone. Have you able to do that yet? - Mike E, Social Media Manager

I assume he means iTunes so tried, after turning the phone off and restarting but the message above is again what I get. Can anyone shed some light? Can't contact Apple contacting AT&T doesn't seem to get me anywhere. Too bad it wasn't a Verizon phone they unlock me in moments, but my previous iPhone developed and bad motherboard and needed replacement and so that brings us to here. A Phone they say is unlocked yet seems to be locked and I'm out of communication with my business for 8 days now..