Been Billed for a CANCELLED SERVICE

I have called the Call Centre on Friday 07 August 2015 to cancel my contract due to the fact that it is running way over 2 years now. The nature of this problem stems from 2 facts:<br> <br> 1.) The fact I cannot upgrade and have been denied that from your MTN system, and<br> 2.) I cannot use the service as MTN does not want to re-activate my sim card as they say there is a problem.<br> <br> After speaking to the call centre agent and asking to cancel my contract due to the fact that it is running way over 2 years now, the agent assured me the cancellation has been put into effect on the system and I need not worry about it. I then asked for a reference number which is then said I must use my cellphone number as the refer and that days date. I have never heard of such a thing ever before. I was assured that the last billing will be the end of August 2015. <br> <br> Its now mid October and I'm still been billed for a cancelled service. I want this looked into and sorted out and I'm not happy about this \new"bill of R600 I'm supposed to pay. <br> <br> Please can we fix this.<br> <br> Regards"