Bad Service

Year before last Tracker was piloting a service and I was selected for it for 15 months after which I had to say if I was happy with it and start paying for it. I was happy with the service and decided to take the offer at R199.00 per month. I was called and informed that some device will be installed next to the steering wheel and to this day that has never happened. Last year I was informed by them that my service has been suspended and I should pay about R700 of which I paid R800.00 in November 2014 lest something happens to my car. On the 03/03/2015 I received a message that I am in arrears again when I called and spoke to Lwazi she advised that it was for the R199.00 service of which I am still waiting the device installation. She proceeded to tell me that according to her the device is installed because she can sky track my car. They could sky track my car whilst they were piloting the service! I want my R800.00 because I paid for a service that I am not getting and refuse to pay R349.00 that they say is in arrears. This is very wrong, I feel taken advantage of and cheated.