Car track South Africa bad service

I have signed up for cartrack about 8 months ago .about 2months later I sold the vehicle. I informed car track that the vehicle is sold and and provided the new owners details. They have told me theres a charge for transferring which I agreed to. That month they debited the normal installment..when I queried again they said they where unsuccessful in contacting the new owner. Iv checked with the new owner and he said nobody called. It's been going on like this for the past 6months. Frustrated and ************* car track has proved they can't get simple transfers done yet they boast of recovering our vehicles. I now will have to close my bank account as all my attempts have fallen on deaf ears. This is inconvenient . Please people beware of car track and their poor after service