Bad customer service,Even Worse attitude!!

I have a cellphone contract with MTN. The sim card does not get used as the contract was purely taken out for the phone. <br> <br> For 3 months I have received a bill of R150 more than the contract amount (The sim is still in m cupboard). I called MTN last month and they told me that I had subscribed to different subscriptions. I explained that the sim card does not even fit into my current phone and that I have had the contract for 4 years and just upgrade it for the phones. They informed me how o unsubscribe and I inserted the phone into an old nokia and unsubscribed. <br> <br> This month the same bill came. I called MTN and the person told me that they cannot control what I subscribe to, despite me telling her that the sim cannot even fit into my phone. I cannot see how a network provider can allow their clients to be subscribed without their knowledge. I do not have this problem with My Vodacom contract that my sister uses. Or my cell C contract of which I use the sim card. <br> <br> At the end of this contract duration I will cancel my contract with MTN.