I am paying for a car that was written off

My car was written off in Feb, I called netstar to notify them about this and they still continued to deduct monthly premiums. I got a new car , and phoned them to let them know that I want it installed on my new car. They told me that I'll have open a new account. Now I am paying for 2 cars, one that is non-existent. I phoned them again to rectify this, and they tell me that I have to pay a settlement fee. I am really not impressed with this as the consultant didn't advice me well. The premiums just increased so am paying more than R400 for both cars, this is ridiculous. I want to change tracking systems.