Sbcglobal.net email account locked

I have sbcglobal account for many years (20+). Sometime ago my account got locked because of multiple attempts to log in with invalid password. Now I can not unlock the account because I can not remember the challenge question/answers.  is there another way to verify that I actually own the account and unlock it?

I used to be able to receive my email at my gmail account as linked account. Recently that account also unlinked the sbcglobal account.

Please help. I have used the email account at hundreds of my contacts over the years. It is a huge loss for me.

Thank you