Debited for a cancelled contract

In February 2018 I took out a contract and I cancelled it in store the very next day. The contract was cancelled in store by the agent. A few days later I called the call center to confirm that it was cancelled. The consultant confirmed that the contract was cancelled and re- assured me that Telkom will not debit my account for the cancelled contract. On the 5th of April 2018 I was debited for the contract that I had cancelled in store in February 2018. I tried calling the call center but after holding on for over 30 minutes there was no answer. I then went in-store and the consultant requested someone to call me. They did and I explained the situation and he said he will request an investigation for a refund of R543.70 which telkom was not suppose to debit from my account. I have called telkom several times, on the 9th of April 2018 I spoke to Sihle Ngwenya and after spending 40mins on the line he assured me that his manager, Noluthando Sishi, would call me as soon as she was done with a call. It’s now been almost 2 weeks and she hasn’t contacted me. Today, the 19th of April 2018, I spent 1 hour on the line and after speaking to Audrey she says the case was not logged initially. Once again I requested to speak to a manager. I then called back because the call was cut off after an hour, once again after 20mins spoke to Thabo, he gave my contact details to his manager, Busisiwe Sibambo, she still has not contacted me. I am now fed up with telkom and I am considering cancelling my current contract with telkom as this is the worst service I’ve ever gotten from a service provider.