Car tracker is eating my money for nothing

Hi my name is Nkosie ndaba i had a car tracker fitted on my vehicle by car track when i decided to sell the vehicle i informed car tracker and they said i will have to pay R850 for them to remove the device and install it to my new vehicle i payed they tool off the device and said they will call me back after 3days to give me a fitment date for my new vehicle they never did ,that was last year october but every month they deduct R160 for the device that is with them not on my vehicle , when call them they transfer the my call to one another until my airtime finishes and not get back to me ,when i started reversing the money they taking they give me calls about my account being on errors i tell the person that calling the story they say they will investigate and come back to me none of them ever did until today every month am paying for nothing i need help i dnt wants them to fit the device anymore i dnt wants anything to do with car tracker my number is *** and my Cartracker ***