Vodacom Won’t Let Me Cancel My Contract, and Keeps Billing Me After I’ve Paid the Cancellation Fee

I cancelled my account and paid the cancellation fee at the Vodacom store in Canal Walk on the 8th of May, and I’m still being billed because nobody seems to be processing these requests. I had just gotten off of the phone with customer support and they confirmed that there were no updates that I had cancelled my contract. So who has the money that I paid? Do I need to report this as theft?