Seven conversations, seven different answers, billing still not accurate

I've been with Comcast for 15 years, and I have never had any issues until the last two months. Between the end of November 2023 and mid-December 2023, I have had to contact Xfinity seven times via phone and chat - and my bill is not what customer service quoted me.

I have been paying $300 a month for quite some time before I contacted customer service to see if there were any discounts or packages I may qualify for without changing anything on my current package.

First contact -  I called customer service and I clearly stated multiple times that I did not want to change any of my services. The agent told me she could lower my bill significantly and I would have the exact same TV and internet package. She sent the agreement document for me to review, and she had changed my unlimited internet to a limited plan. I denied the agreement. The agent added unlimited internet back to my package, and I agreed to the contract. 

Second contact - The next day one of my cable boxes was not working. I called customer service and the agent stated that the cable box was removed from my plan by the first agent. The agent added the cable box back to my plan.

Third contact - I called in because I no longer had Showtime on my plan.

Over the next week, I had to contact customer service multiple times. The first agent had completely lied to me. My cable box was disabled, Showtime was removed and then HBO had been removed from my package (one chat agent said that my old plan had HBO but my new plan did not include HBO). Again, this happened when I clearly stated multiple times that I did not want to change any of my services.

On 12/15/2023 and 12/16/2023, I contacted customer service via chat and on both occasions I had to tell the agent the complete history of the absolute mess I have had to go through because the agents said that they were unable to pull up previous call notes or previous chat transcripts. I do not understand how that is remotely possible. The chat agent I spoke with on 12/16/2023 wrote: "Agent (02:38 am): Yes it is already included in the bill and your final bill will be 236.24$/mo for Internet speed upto 1000mbps with unlimited internet speed, 185+ channels including SHOWTIME and HBO MAX. You will have 1 Modem + 2 Tv box included in your bill." I have the entire transcripts saved.

The last agent I spoke with spent a good amount of time with me to review what had happened, which I appreciated. The agent reviewed everything with me and said my plan would go back to what I had before the first contact. Unlimited internet, cable tv package with HBO and Showtime, and both cable boxes in my home. The agent even applied a one time discount for the trouble I had to go through.

I received an email on 01/16/2024 saying my bill statement is ready and the total due amount is $286.23. 

I just can not believe how I have been treated after being a loyal customer for 15 years. On every conversation I have had with Xfinity in the last two months, the agent has told me it would be the last time I would need to call about the same issue. 

I am so exhausted, disappointed and frustrated by this entire experience that I do not know what to do anymore.