AT&T Yahoo account login problems

I have called and chatted with AT&T several times (well over 4 hours now) about this problem.  It would seem something happened earlier this week or last with the way ATT connects with the Yahoo backend system for email authentication.

When I try logging in from the Yahoo!mail page I get the endless username > password > username > password … cycle with no indication that there is a problem other than it keeps asking for username so the login never passes.  When I try to login from ATT.NET I get the ATT login screen but now I get the error "Your account has been loced due to too many failed logins.  Please, contact AT&T operator" but they do not explain the best way to do that and no one in regular tech support areas now how to help.

Back many years ago several pre-AT&T RBOCs (mines was SBC) allowed customers to create accounts under the @yahoo.com domain.  Now it would seem those accounts are orphaned - not in the Yahoo system and now not in the AT&T system either.  I have an att.net account that works properly so I know they still have the connection to the Yahoo backend system.

I am trying to figure out how to do one of two things:  remote the ATT link from Yahoo so it becomes a regular Yahoo account or 2) re-establish the link so Yahoo can see the underlying ATT account even though it ends with @yahoo.com rather than @att.net.

This should not be that hard for one of the largest companies in the world.