Poor service and attitude

I ask Golf Wizard to install a Golf Gti 2 liter in my Kia bakkie. After I received the bakkie back my vehicle started to make a stranger noise and the motor cut out. I tried contacting the installeer by name of Johnny, no Surprise he did not answer me. I then took the vehicle to another Mechanic who informed me that the timing belt snapped due to the timing tensioner bolt pulling out of head. This lead to all the valves bending. I once again try to contact Golf Wizard with no success. I even sent him whatsapps without any success. What to do next?