Been overpaying since february of 2024 and xfinity wont refund me whats owed, Who do I turn too???

I called in and told the agent that I only wanted internet in feb- 2024. my box's where disconnected that day and not longer had access to tv. I admit fault in not turning them in for a few months as I forgot. I thought my bills where higher due to the rentals of the box's still being charged, two of them. I returned them at my local store a few months later. Not once had I watched tv and couldnt as it was disconnected. I realized this in january. I have been reaching out over the phone and online and for no reason. After 20 or so phone calls and countless chat agents that disconnect when you almost get some where or just tell you what you want to hear and no action,  These CLOWNS could not fix it. Finally i went into their store in person where i returned them at. the guy looked into it and said yeah you have been being charged for a tv and phone package and espn plus this whole time. He told me i was owed approx. 2700 dollars. Ive submitted a ticket and they finally got around to it 10-12 days later. inbetween this 12 days i had contacted MANY chat agents and called in as well, None of them gave me the same answer. Some said i would recieve the 2700 and others said nothing. Long story short, i received a phone call from a customer care agent today, The lady on the other end said she didnt have to go and back date anything because i didnt sign off on the change of services request??? and that i would have a credit of 700 dollars...... I should have only been paying for the 109 dollar internet package and a 15 dollar service fee according to the agent i talked to in the store. I was paying close to 250-300 every month.... the agent said i should basically be thankful she was doing that. I told them to pause this while i seek out legal resources and double check all the bills. she said i have until monday to make a choice, thats only two weekend days as today is friday. I told her you took 10-12 days, I get 10-12 days.......

Im not asking for anything that isnt unfair and just what i paid for that I could not even have watched since I dont have ANY tv boxs in my house. The lady was very rude an basically made me feel like i should be greatful and that I needed to make a quick decision on the spot after they took sooooo long. 

Has anyone else been through this and what was the resolution and how do I go about it???