US Cellular Customer Relations Charging us for service we could not and did not use AFTER we cancelled our service Dallas, Texas

I work for the Army. In September 2011 my family and I were moved from Oklahoma to Utah on military orders. We discovered after getting to Utah that US Cellular does not service Utah. We emediatly contacted them to find out what had to be done to discontinue our services. After my husband, the account holder, spoke with an agent confirming the request to cancel, I spoke with them about what had to be done to cancel the service. They told me the documentation required and gave me a fax number to send it too. Within 3 days I faxed the documents to the required number. I also paid our account in full. In October 2011 we recieved a bill for October. I called customer relations again and they told me the documentation was never recieved. The agent gave me a fax number that was directly to customer relations. So again, I faxed the paper work. In December 2011 we recieved another bill for two months of service, October and November as well as a cancellation notice by the company for lack of payment. I called again, spent at the least an hour on the phone with an agent and a supervisor. They stated they still have not recieved the documentation. I verfied both fax numbers with them. The next day I faxed the documentation to both fax numbers to include a conformation sheet from the last time I had faxed it. Sense then they have been calling me ever day demanding payment. I called them again yesterday and spent an hour on the phone with them, again. Only this time they are claiming they never spoke with the account holder and he is the only once who could cancel the account. They claim it was not in their notes therefore the bill is valid and we will have to pay it. Never mind the fact that I have spoke with them several times and faxed the documents 3 times. Now they are saying we only have to pay for one month or they will turn it over to collections. Shannon Tooele UT