Cancelation of contract.

I'm not sure if anyone else has experienced this problem with MTN as l have but lm going to let you know what's going on. I have been trying to cancel my contract with mtn since Debruary this year. I call them and spend hours on the phone being transferred from one person to the other verifying my details several times and as l get to the last person the call gets cut very conveniently and there is no courtesy to call me back. They have been continuously deducting this contract amount and l have not even used this phone as my Sim is blocked and they have given my the incorrect puk number. The local MTN shop in Chatsworth KZN are most unhelpful people and have done nothing to help me. I'm now tired of them, despite the many emails l have sent l get no response. Kind Regards R Naidoo