Trying to Cancel my Contract Since June 2015

I have been sending the cancellation letter to them since July 2015, my contract has expired in May 2015 already. Went in to the shop and they said because on the second e-mail I send, I asked why the contract was not cancelled, that did not give them instructions to cancel it. So their instruction was I need to send a new Cancellation letter and they will action it (this after that consultant screamed at me over the phone). I did this and still no cancellation, even received another invoice for end of January. I need this contract to be cancelled and want my money back since July. We have not been using this contract since May 2015 because we cancelled it. At the call center they give me an address that does not work. I have sent the cancellation there 4 times already as well