Cancellation Process frustration - not possible to cancel my expired contract.

I've had excellent service from MTN for years. Unfortunately, MTN signal in our area degraded to such an extent that I need to switch to Vodacom.

The cancellation process is however a huge mess. I contacted customer care yesterday stating and went through the cancellation process. The system froze and the lady said that I just need to hold the line. Then all of a sudden the line just disconnected (this was after the previous lady just hung up the line and I had to call back again). The lady never contacted me back and you need to wait about 10 minutes before you get to the correct department.

I then called back today to confirm whether the cancellation was loaded. Today I was told that there is an outstanding balance against my account of R1 100 and therefore I can't cancel (please note - my contract have expired already and I am therefore on a month-to-month contract). I apparently need to call back on the 2nd of February to cancel. But why can't a future cancellation date be loaded? Surely this should be possible - I've been working with Vodacom for a while and with Vodacom it is possible to state a future cancellation date one year in advance.

This is honestly frustrating as from there is less than 20 business days before the next billing date (as per MTN I need to give 20 business days notice).

Thus I am not sure if I will once again run into problems to cancel my contract on 2 February. Also, according to me it must be possible to cancel a contract on a future date (especially if it is within the next month).