I sold my car over a year ago

I sold my car over a year ago. I cancelled netstar. And yet they are still debiting me R95 every month. When calling them, multiple times because the calls are always dropping, they tell me that netstar is cancelled but the add ons are not. Two months I cancelled the add ons but still I’m being debited. Pathetic horrible service, I don’t have half an hour every day to waste on phone calls to keep cancelling the subscription.