Bad service

Telkom called me to upgrade my contract as it is coming to an end.I specifically told them that am not interested to upgrade. They have been debiting on my account since as I know the contract has ended , I called to be advised. They say they don't cancel contract even if it has ended customer is the one that supposed to cancel which is insane and they keep suspending my service.also I got a call from their agent to take data contract which Itook becauseit was affordable but now I can't get hold of them to cancel my contract. How does this make senses? I. Be warned of Telkom, they are ******!!