Refusal to cancel a contract

It has been three months now that i have been trying to cancel a very old data contract with Vodacom. Every time i call the call centre i get chased from pillar to post and get told things like "we cannot assist you because your number is on an old system", "my supervisor is not here" and " we can't assist you with the reference number for your old calls because i am not on that system".

All the while though, i keep getting invoiced for this contract and i have never been asked if i want to extend it past its sell by date.

This evening again, i was chased around (at least this time they did not try and sell me a new contract), and again, i was not given a reference number for the call.

Eventually i was told i have been sent an sms saying the contract is cancelled - i have yet to receive this sms. When i asked about the matter of refunding the invoiced amount after having previously trying to cancel the contract, the operator said it was his knock-off time and put the phone down