Non cancellation of expired account

For a wannabe reputable mobile division like MRP Mobile, they are *********** and ****mish and should just close down this Mr Price division because it will bring the whole of Mr Price brand down. They cant handle a simple request to cancel a long expired contract just because they want keep making money and keeps the contracting running on a month to month basis. My contract ended in August last year. I submitted numerous request both email and phone calls to cancel the contract, but they delayed their responses so that they ensure that he account keeps getting billed and then tells me that its in arrears and I need to settle the amount first, whereas its their fault in delaying timely cancellation. From a R99 I was paying, I recently paid R780 (eft plus debit orders I authorized) to try to cancel the contract. This amount is double what I actually owe on this expired contract, but still despite my latest email request to cancel the contract, they is no response again, until the account bills up again, then I am told of arears to clear first. This is a ****mish cycle of *********** group that should just close down.