I have been to the email you list above. The answer I get when I put in my user id is:
Error: We do not have sufficient security information to verify your identity with the online password XXXXX tool. Please contact Customer Support to have your password XXXXX and then log in to set-up your account security information. For further details on resetting your password XXX what information is required to reset your password XXXXXX see the following help article.
When I go to the next link it gives me a phone number to call ATT that told me to go support.att.com/freememberid and I cannot get there.