Can't Sign In to sbcglobal.net Accounts

At one time I had AT&T and set up three sbcglobal.net email accounts that continued for years after no longer being signed up with AT&T.  Over the last three months I can no longer access any of those email accounts.  I constantly get a message about the Password being invalid.  And when attempting to reset I have had trouble answering the security questions.  It has been so long since the questions were set up that I no longer remember the answer to one or two of them.  Im desperate to be able to access the email accounts and have no idea of who to contact to get the password reset, especially with the problem with the security questions.  Help!  It seems I'm not the only one experiencing at least part of these issues.  Did something change?  Is there anyone at the Yahoo level to contact?  I really am at a  loss.