Uverse account versus separate DirecTV account

I have ATT Uverse at my mother's house.
I have DirecTV at my house in another city.
I handle my mother's finances.

When I go to ATT.com and log in.... I get to my DirecTV account.
I've tried to manage the Uverse account but can't seem to access it.    When I tried to create an account to access uverse....it claims my cell number is already registered to another account.

It is a catch - 22 situation and it is very frustrating....almost as frustrating and the 30+ minute wait when you try to call the technical lines.