Charged for over a year after disconnecting services

Who should I get in touch with to finally resolve my issue with Xfinity accurately disconnecting my services? I moved out of my apartment Oct 16 2023, and I have continued to be charged on a monthly basis to date for Xfinity despite not using the service since Oct 16 2023 and calling 5+ times to get this resolved. Multiple times I had my services confirmed as disconnected, yet continued to be charged. I finally got through to someone four days ago who confirmed yet again that it had been confirmed as disconnected as of Oct 16 2023, only to view my bill today and notice that it had in fact been incorrectly noted as a service discontinue date of Oct 16 2024, meaning that I would be missing a year's worth of refunds for a service I was not using. I then tried to reach out via Xfinity Assistant and was told that 'everything had been updated and I would receive a refund after returning equipment.' I 1) never received any equipment, and 2) after noting this to the agent was told that this would not be an issue and the ticket had been resolved. I just received notice that the refund was not accepted and ticket has been closed.

Who is the appropriate person to get in touch with in order to resolve this issue and get the $1585.15 that I have fraudulently been charged by Xfinity refunded to me?