No response to cancellation of contract

I have phoned MTN for more than five times today with my calls getting cut off everytime I do. I have a concern/problem with the fact that my contract expired on the 05 July 2015, and I asked that my number be migrated to prepaid. I then received the above ref. number (***) during one of the conversations with their staff members, where on the last call I was told that I would get an SMS to confirm the migration within 48hrs. It is now more than a week and I still have not received the confirmation. I wish to state it clearly now that I will not make any payments to MTN should they decide to continue with the contract disregarding the fact that I called many times to cancel the contract.<br> <br>