MTN has gone to the dogs!!!!

In mid-January 2015, I renewed my mobile contract with MTN, as my previous SP, Nashua Mobile, had closed down.The contract I opted for was a straight forward Top-up plan that MTN was advertising with the only extra being Itemised Billing. Up until 01/06/2015, MTN had been billing me for hardware fees that was part of a contract that I had with Nashua Mobile and had expired on the 19/02/2015. Every month since Feb, I have had to go to the MTN branch and request that the H/W fees be removed from my renewed contract and also that the \UNAUTHORISED"charges be refunded. Every time I submit a request for the refund"