Cancelled Services - CAN'T SPEAK TO AN AGENT.

I moved in October to Arizona - where we do not have access to Xfinity. I RETURNED ALL the equipment before my move date, told them to cancel my services IN PERSON. I continued to get emails saying to pay my balance or my services will be interrupted. I CALLED TWICE to tell them I canceled my services. Then, I get a letter in the mail saying my services will be turned off on December 15th - the services I ALREADY CANCELED. Now, I cannot chat with anyone to that it is in writing that my services are canceled NOR can I even speak to someone on the phone without paying the past due balance for services I ALREADY CANCELED THREE TIMES. I need to get in touch with someone to get this straightened out.