I have 300.00 in bad charges on my bill. Xfinity Assistant and Call backs are not rectifying the situation

I have bad charges on my September and October bills. I have been speaking with the billing department since 11/5/2025 to have this resolved. Every time I speak with someone and go through the entire explanation, the phone line goes dead. Then I have to restart the callback process. I started asking the rep who calls back how I can reach them if we get disconnected, and every one of them said they will certainly call me back if that happens, and they repeated my phone number to confirm. I spent 3 hours doing this with 4 different representatives Saturday, November 28th. Each call was dropped and not one of them called me back. I have a ticket number that has been opened and closed multiple times: ticket # [Edited: Personal Information]. I generally like the services that Xfinity provides, but this experience has not been a good one - and I am not going to pay erroneous charges to keep my services active. Please help me get this solved.