Hello, CarolCo!
Thanks for posting. I'm sorry to hear you're having difficulty accessing the online account management system. The app that the care rep was recommending was the myAT&T app; it allows you to manage your account from your smartphone and would likely be a good option as a temporary fix. For more information about the app, click on the link below.
What browser are you using? Have you tried a different browser? We would be happy to look into this for you, so please click here to send us a private message with your contact information, the best time to reach you, and a brief summary of the issue.
You can expect a reply within two business days, so keep an eye on the little blue envelope icon in the top right corner of your screen. In the meantime, feel free to message me with any other questions or concerns.
-Mariana