On October 22, 2015, I called AT&T customer service to help me lower the monthly bills as the initial plan was 15GB yet had been using less than 2GB. It was changed and the CSR said that will reduce my monthly payment approx $40.
On November 3, I saw online that my actual monthly bill INCREASED $32 higher than when I called the previous month, an $80 difference. The AT&T representative looked into it and found that the October change took one phone that was off contract into a two year contract which ADDED $40/ month to my plan.
I have been an early adopter of cellphones using AirTouch which became PacBell which became SBC which became AT&T ... 25 year history and treated like crap. If this matter is not resolved, I walk away.