NO RESPONSE EVEN FROM ESCALATIONS

I have been trying to cancel my soft cap 20gb internet from Telkom for exactly 6 months .Every time I call to cancel they tell me its done and I BELIEVE THEM but low and behold it appears on my statement every month.I have complained for 3 years now about my usage being far too high as I don't play games and they just say its your IP address. My complaints have been escalated but they just ignore it. I can see that it is read but NO RESPONSE. Where does one go from here. I stopped paying and they cancelled my line.