Telkom Worst ever.

How can Telkom Bill me for services that were not rendered? I just received a bill\invoice and a contract that is non-existence. A contract that was cancelled within the 7 days testing\cooling period. The data contract that I have never even used and the devices that were picked up from me already thus confirming cancellation? The worst service ever and they are inconveniencing me since what they are doing will impacts my credit ratings going forward.