Email Password Reset Won't work for accounts with one character in last name

I have had this account for at least 15 years. The password reset requires at least 2 characters of last name, however, the last name on my profile is only 1 character. Calling support multiple times and they can't add another character or reset my password so I am locked out of my email account. What to do?? At this point since ATT support is not helpful I will look to cancel my Uverse internet and TV and find another provider who supports their customers better.