MTN cancellation ****

I "have" a contract with MTN that has run it's 24 month course, I have not renewed nor made an upgrade as I knew I was leaving the country. I kept the number active as I would be using roaming until I could find my feet abroad and get onto a local network. Trying to tell MTN to stop debiting my account is proving impossible. I have on numerous occasions sms'd the cancellation request number, I have tried phoning them (Not convenient as there is a 9 hour time difference). I have emailed, to which I received a reply asking for the number I would like to cancel as well as my ID number. This I supp****, nothing happened, I followed up, no reply, Every month R900 is taken. This is ludicrous and amounts to *******. How many people are faced with a similar scenario? MTN just takes and takes