Can't log into my sbcglobal.net email account

 I have been locked out of my sbcglobal.net email account that I have had for over 20 years.  I get the message I've tried too many times, all the reset password efforts have failed. They want to send an email to my sbcglobal.net email to get a verification code, obviously I don't have access to that email to get the code.  All else has failed. Called att they say it's a yahoo problem, called yahoo they say to call att. Noone can help me. I've been trying to get into my account for months. It's causing so many problems. Please tell me who can I contact to get access to my email.  thank you