Cancellation of contract nightmare

We have left South Africa in February 2016. My husband's mobile contract has expired in 2015 already, but we changed it to the minimum contract available and selected to keep it running on a month to month basis until we are settled abroad.

We are trying since January 2017 to cancel this contract by email, on the website and via numerous phone calls, but no joy. We have cancelled the debit order with our bank (they can only do it for three months) but Vodacom is persistently taking their pound of flesh monthly for almost two years now.

On top of that, we had TWO price increases on that cancelled contract since we left SA. We are SO disappointed in their service, it's absolutely a joke! We would really appreciate if we can get this resolved now?