Contract term completed for 24months

I called MTN about two months ago to inform them that my contract had been done on the 10th February 2015. Due to me not contacting MTN there were debits still going off my account which to me had been incorrect. I called MTN held on for about literally an hour and spoke to someone in the contract cancellations department with regards to cancelling this contract. I had requested that this contract be cancelled as Im not looking at upgrading with them. I was given a cancellation *** and told that this would take effect. To my surprise i receive a call from the accounts department to state that i am in arrears with an account that should have been cancelled an that my account would be softlocked knowing full well that this sim card has never been used in the 2 years that I had the contract because this was merely for the phone. I want someone from Head-office to call me regarding this because I have been handed over for something that should have been sorted if MTN had more effective working staff taking calls and capturing details on the system.I find this totally unaccepted and working in a service industry the quality of conversation with a customer is unacceptabl