I do not know how to initiate a chat with AT&T tech support, since I do not have an AT&T telephone number.  I called the 800-331-0500 number and got a most unhelpful "Bob" who was pretty sure that the only way any iphone can be unlocked on AT&T is to purchase it unlocked at the store.  He kept repeating the same thing a couple of times.

I had purchased my no contract at the store and it is still locked.  Any help is appreciated.  Perhaps I should try again and hope to get to someone else.