Contract not cancelled

I phoned MTN SP to cancel my Anytime 500 contract which was well into the month-to-month renewal period. I was quoted reference number ***. I was told that my account would be migrated to prepaid within a few days and that ongoing contract expenses will end. When I log on to the self-service contract portal, there is no indication that my contract has been cancelled. I have emailed [Email Removed] on 2 occasions in order to confirm that my contract has been cancelled. Both times, I received an error message from their email server telling me that my message was undeliverable. I have received no other communication or acknowledgment of my request for clarification. I have emigrated and do not wish to incur long-distance call charges on the phone to the call centre.