Disservice and xfinity can't do anything

I've been given a disservice and been put into a contract that wasn't what I was offered. Forced to pay a bill and stuck with a phone that was supposed to be free. Ridiculous how a big company does not have anyone that can help. I've even gone to the xfinity store in Danbury ct and even the sales agent can't give me a straight answer as to why this happened and no one not even the manager can seem to direct me to the right person. The sales agent. The manager and I have screen shots of the conversation I had with an agent through a chat offering me a free phone if I switch my land line to a mobile line. That I'll even save 20 dollars a month. Which ended being a total lie. A month later I'm being charged for the phone and a month later i find out its too late to return it! On the screenshot I clearly asked. I'll be given an iPhone 12. For free. Not extra cost and save 20 dollars a month. The agent response was yes that's correct. That I would a one time charge of 49.81 on my account which is a hold until the phone is activated! All in the screenshot!! I do not need this phone. It's still new in the box untouched because I have a phone! Did it to save myself money but xfinity did the opposite!