U VERSE Login Error

I am having issues using my U-verse login information to login into specific apps. For instance if i want to stream ESPN, NBC SPORTS, TNT etc on my phone you would need to visit (espn.com/activate, nbcsports.com/activate etc) and use the code the app provides you. After you enter in the code and hit submit it's suppose to take you to at&ts login screen, but for every single time i want to do it i get this error message. EVERY SINGLE TIME. This has been going on for a month now literally and i tried calling AT&T's customer service but they did really understand what i needed help with. Please advise.