Installation Went Wrong!!!

Cartrack Polokwane technician ruined my car. after the installation, my car's reverse sensors are no longer working I contacted the technician and he asked to call me back in an hour and a week later he never called back.

I then contacted the helpline then the ticket was created and a week later no communication. There were so quick to get me the contract and installation but I am left with a s**** which they are not willing to help after they destroyed my car wiring.