Vodacom is billing me for a service they not supplying

Vodacom installed fibre at my residence in December 2018. The techs left site saying that they need to provision the line on their end and that it would work in 2hrs. This never happened. After 20 phone calls to their customer care line I was told that there was a fault on the line. 2 weeks went by and I asked them to cancel it as it never worked. They have billed me every month since December even cutting off my cell contract. They are still billing me for a service that was never received. i have logged numerous calls and spent hours on the phone with no success. Be warned.