Xfinity Scammed me

I recently found out xfinity has been charging extra for a device I bought in the store to activate (iPhone 11) I was informed at the store that I was unable to use this device under them bc my device was sim locked by previous carrier I had, so I opted into ordering a brand new iPhone 14 Pro from them. Upon receiving my iPhone 14 Pro and activating it Xfinity unknowingly to my surprise had added my non-operable iPhone 11 as a line on my mobile billing. At first it was $10 added onto my bill so i obviously wouldn’t have noticed it but after adding another phone on my line I noticed it said 3 lines active so I spoke with an xfinity agent who said they’d remove the iPhone 11 off the account meanwhile I never knew I was being charged for that device monthly. So fast forward some time down the line I add a tablet onto my plan at the Xfinity store. I was informed that the iPhone 11 line was still open on my account. I asked them to remove it bc I was informed by another individual that the iPhone 11 wasn’t compatible to be used by Xfinity. They confirmed it was probably a mistake on their end. Months later I notice my mobile billing has been higher than normal so I do my research and find out I was being charged for the iPhone 11 line which in fact was never activated under Xfinity. I spoke to Xfinity multiple times and they are telling me there’s nothing they can do to help me other than remove the device off my account which I was told was done on 3 different occasions and add an Apple Watch for an additional $6 a month. The excess amount of money and time wasted is ridiculous. The lack of American support text support representatives and phone support representatives wasn’t a help at all either.