Problems unlocking iPhone 6s
My girlfriend recently bought a new iPhone with AT&T and paid off her old one (the iPhone 6s). As she did not need it anymore she gave it to me as I needed a new phone. We tried to go through the device unlock portal only to have the request denied both times for too many requests (received email saying "You've tried to unlock this device too many times. Wait 30 days and then submit a new request"); we only submitted two requests in total and she said that she had not tried to unlock her phone at all before since she did not need to.
What do I do?