xfinity mobile billing

I have never, ever had so much frustration over paying a bill. When I first got the service, I didn't realize they put it under my son's account instead of mine. I manage my son's account because he is disabled. Fine. No bill, no email, nothing. Just suddenly the phone is unresponsible. After that I really thought I set this up for automatic payments. Apparently not. Even though I even went out of my way to check to see if it was paid. The balance showed $0, yet when I went to print out the bill, it showed I was overdue by $40. Went to pay that over the phone. It said it had to verify my number. I never got the txt. Tried twice. Went to pay over the phone, said it wouldn't use  my perfectly good credit card. On line chat went in circles with no success.  I ended up on the phone repeatedly saying agent and representative until I finally got someone. They needed me to do it by credit card, which I entered. They said it wasn't automatic payments. You would think with one web site you could pay a cable and mobile bill. While it's a deal to pay $40 a month it isn't with this frustration.