Cartrack, being forced to pay for a service not received.

I joined Cartrack over a year ago and in that year, I have had nothing but problems. The app doesnt work, I am unable to track my son on his bike which caused SO much stress and put my son in immense danger. I have complained numerous times. The logs are also always saying NO GPS and the reason why I installed the tracker was to make sure he is safe at all times, and when needed I would know where he is to assist. However, this service was NOT provided. I have now requested to cancel but they are charging me just under R3000 for cancelation fees. If I had known the company would not provide these services as promised, I would never have committed to the 3 year contract. When the refitment was requested in December, the technician didnt show, more than once! And the fitment was only completed in January. Now, they want to charge me R3000 for cancelation fees, but dont take into consideration all the months the devide was faulty, did not work.