I have an old Galaxy S2 I gave to a friend so he could try T-Mobile Prepaid. I forgot it was locked, but I just called AT&T last night and said "I would like to unlock my old Galaxy S2", answered a few security questions so they knew it was my phone I was unlocking, asked for the last four digits of the IMEI, they looked it up, badda bing badda boom, read off a code for me. My friend hasn't had time to try the code, but I think the whole phone call was maybe 5-10 minutes including a few minutes on hold waiting for an agent.
For everything else, I've been transferred to 3-4 departments before they found the one that could help me. This time, it was the very first person to answer the phone.
She showed absolutely no curiosity as to why I was unlocking my old phone, and I offered no explanation.
It was very much a "please help me unlock my phone", "Absolutely, sir! Let me pull up the script for that and get this done as fast as possible for you!" transaction. I was very pleasantly surprised.