Telkom's activation of unrequested data package

On 19 February I upgraded a mobile data contract with Telkom from 30GB pm to 50GB pm. When I received my bill at the end of the month Telkom added a new 30GB subscription to my account along with the upgrade. Since then until now they have been deducting R609 pm for this 30GB contract that I have not requested nor have ever used. All correspondence so far have been unsuccessful. I have stopped my debit order last month and within a few days Telkom stopped my 50GB data package. Telkom keep on sending me an account charging me for both packages. No one from Telkom has contacted me to try resolve the issue.