New ATT Customer having problems making an HBO GO account

I just switched to AT&T last week. I've been trying to create an account on HBO GO since last Friday with no luck. I'm using my att.net log in and password and have HBO included in my plan yet   it keeps giving me an error code saying my account doesn't include it. Also, it is now not even prompting me to type in an ID/password when i try. It's like its stuck or something. Please help.