Tracker not liable

Hello Peter..I bought a polo vw from MBA auto in May2017..It was only after I installed tracker device from potchefstroom branch the car has been giving me problems..I took it to Volkswagen workshops with my own costs of R3800 where they discovered the wiring of the tracking device was joined with the wiring of the fuel control unit coursing it to temper with it where it was replaced and the tracking device been taken out..I then counter claim the costs to the branch bt they failed to assist me telling me to call headoffice with my costs again when I ddnt even install the device at the head office but them..They pursed to install the another device when I opted them to cancel my contract..It was in December 2017 and now the car is giving me same problems which was last week discovered at Volkswagen workshops..They want me to cover the costs because it was due tampering of wiring from the tracking device..I am now stuck with the car being liable at Volkswagen because Tracker doesnt want to cover the costs again..

I still have all records and can hello peter help me resolve this.