Having trouble closing out contract after moving to an area not serviced

I submitted the cancellation due to moving form sent to me after calling customer service on August 29th. I faxed the form, a copy of the lease where I was moving, and a print out from comcast.com that showed they did not service the location. I was told it would take 60 days to process. I returned my items and kept the tracking info so I know they were received early October. I got a bill for a monthly payment in November which prompted me to call and I was told they did not receive any of my cancellation paperwork. I spoke to someone who appeared helpful at the time and gave me her email to resend my paperwork and lease. I did this on November 5, 2018. I received a letter of a past due balanced in December so I called again. The person I spoke with this time, reassured me I would not be sent to collection because it said I was in the cancellation process. Well in Janaury I receive a letter from a creditor, that was sent to the old service address not even the updated address that they had on file. I called and disputed it and then call comcast again. I was told by the new person I spoke to that he could see all of my forms even from August, but was unsure as to why they were not being processed. He assumed the lease needed cleared documentation so he gave me his email and I had the landlord redo the lease. It has now been almost a month and the two people I have been emailing with have gone dark. I will have to call comcast again and speak to a new person. There has been no resoltuion or communication on their end as why they are not accepting documentation they said they needed to void the contract and zero out my balance. This has been a disasterous process and I have documented every fax, phone call, and email that shows how often I have tried to resolve this according to the copy of the contract. I'm looking for help with my situation and a solution.