DSTV taking unauthorised monies from people who are not customers

I was a DSTV subscriber. My decoder was insured through the company. I cancelled my DSTV subscription a year or 2 ago. I also cancelled the insurance. My experience with DSTV is not good. They are are competent in getting things done. Last month R43.92 was taken off from my account for insurance. I got the bank to reverse this and it cost me some money to do this. This month They have now change the amount to R51.33 and the monies have gone through my account again. I know that they have lost a lot of subscribers but I think that this is ridiculous in billing people who have cancelled their accounts a long , long time ago