Contract Cancellation

I've been in dispute with MTN for the last 9 months as my contract was due to end 31/01/2015,I had contacted the call centre to confirm that it would be cancelled, I was given confirmation and requested to RICA my number during the month of February but to my surprise I've been receiving monthly statements after I was given confirmation that the contracted was cancelled, I'm utterly disgusted with the company as I have been liaising with their legal department as I've been receiving communication that my account has been handed over to debt collectors, when I request for information as to their legal department advising me where in their terms and conditions does it state that a contract will be moved to a month to month contract they are unable to provide me with the information, I've therefore started consulting with a lawyer for as this impacts my credit record.