Worst Fiber Provider - Non existent service

It's been over 12 months of being billed for a service that was changed to a prepaid service. I've disputed this issue for months to no avail. I have requested cancelation and Noone has contacted me and it's been about 5weeks. The case is still unresolved and no updates provided, I still owe R6000 for a prepaid service that I pay for in advance before using... Honestly the worst business operating in SA currently.