Unknown user and TV account on my U-verse profile

I logged into my account at att.com. I went to my profile page. I saw my TV and internet account number. There was also my email address, phone number and physical address. However, when a scrolled down a bit further, I found a TV account (different account number) with a phone number, email address and physical address that I don't recognize. To the left of that information, it says, "You have primary access of this account." It has links to edit all that information, plus the passcode which is asterisked out. I tried using my information to change the passcode, but it failed. That tells me that someone else has access to this. Why is it displaying on my profile?