VERY BAD Customer Service and Charging Wrong Bills

Very bad Customer Service and Continuous wrong billing of Xfinity .
I strongly suggest not to have any service with Xfinity. I will definitely cancel my service once the current contract ends.
Here is why

I trade-in a phone and had a discount of $499 which will be spread in 24 months (the contract period). However, starting from the first bill till this month, the discount never applied and I got charged the full price of the phone I received from Xfinity for 9 months now. I contacted customer service repeatedly (more than 10 times since July 2024, the first bill starting) via chat and over the phone. --The automated chat never resolved anything. 
-The virtual chat with agent also never resolved the issue. 
-The agents on the call I spoke to, all wasted my time by asking so many questions and say "let me transfer you to another department" and kept being transferred upto 4 people and none resolves the issue. I once even stayed on the phone for 2 hours and 35 minutes being transferred form one agent to another and a lot of HOLD time in between, and none resolves the issue. Somedays I get tired of waiting for hours and hnag up the phone & go back to work
-The Xfinity Stores I went (3 of them) told me, they can't handle billing issue and told me to contact Online or Phone agents, who didn't solve the issue as I noted above.
I finally realized that Xfinity intentionally made the customer service (mainly the Online & Phone Services) too lengthy, so customers can't handle and drop their request and Xfinity kept charging money. So, I found that this is a deliberate cheating on their end and I will take this case to the legal entity that I can afford and claim not only the wrong bills, but also a compensation for all my wasted time of dealing with agents. Meanwhile, I strongly recommend for any new customer NOT TO HAVE ANY TYPE OF SERVICE with Xfinity. It can't get bad any more than this and I can't wait for my contract ends and switch to other service providers both for my Phone, TV, & Internet Services. Xfinity feels that they are the only Company that can provide these services and do whatever they want, including continuing wrong bill charges as they want to. Hell NOOOOOO