Telkom does not want to acknowledge that they owe me my hard earned money.

I am at my wits end here. I took a contract with Telkom sometime in April at the the Trade Route Mall store. I then returned the device the following day, and they logged a case for a cancellation on the 20th of April . The person who was assigned to this case took time to process the cancellation and when they finally did I had received an invoice despite being told that the fees will be waived. At the end of the month I was debited the full amount of R829 instead of just the R199 I was due to pay. I got a case logged for a refund it was closed because no proof of payment was attached and nobody bothered to tell me about it and they just closed the case. I got another case logged on the 12th of June 2022, still nobody bothered to call me to update me about my case. My case has been closed because apparently no refund is due to me despite me being incorrectly debited and I have attached all the proof I have. Despite my many attempts to contact them nobody from the billing team has contacted me because clearly the ID10T that was assigned to my case did not even bother to do a proper investigation. I will be damned if they think I will just leave my hard earned money like that.