Complaint

I took up a contract with Netstar for a tracking, a few weeks ago I called them as I no longer have the car, and was advised that I need to pay a settlement fee since my contract has not ended. My issue is I lost money on the purchase of that car and are asking Netstar for a discount on the settlement. The consultants in the call centre are rude, the manager is unprofessional and has failed to return all the calls he promised to make regarding my query. I need help cancelling this contract, I have through enough thanks to VW for selling me a car that was written off.