Had problems when I brought the iPhone 17 pro for my son months later the same problem with the 18 pro max

I’ve been with Xfinity since 2017 I used to always get good customer service , this pass year I can’t say the same. In July of 2026 I was double charged for the iPhone 17 pro a phone I gifted for my son . September of 2026 I purchased the iPhone 18 pro max now all of a sudden I have late charges and all kinds of things, who has a $368.00 bill with Xfinity me that’s who . Been on the phone for 2 hours and nothing has been resolved.