Paying cartrack while tracking device is faulty

Hello I bought an Isuzu kb250 double cab 2018, November 2018 and the dealer insisted to install a car track tracking unit, i have been paying my installment R189 every month, but when ever i tried to log in with the app, the car was stuck at one place. I reported the matter to car track and they checked the system and said that my unit is faulty they will send a technician to repair it, that was in February and they never sent any1 and i was in Kimberly i tried calling their bruch in Kimberly to set up an appointment, no answers and to one returns missed calls, end of April one of their call center agent called me and apologized for the inconvenience and disclosed that in their records they dont have a contract with me and they would like to do things right so they want me to sign a new agreement and i agreed and waited for them to contact me to sign but nothing happened.

I have been paying car track for 5 months while they didnt even have a contract with me, in other words they have been taking my money ********ly and i never got, good service as my unit was never working.

I want car track to pay me back my 5 installment in cash as they where taking money from me and never gave concern to the faulty device and the fact that they lost my contract.

My number is ********** ********** 766220