ABSOLUTELY DISGUSTING SERVICE!!!!

My car has being sent in for repairs at Mini Cooper Claremont as the car being within their care something gets sucked into my turbo/turbo pipe and messes up the turbo of my car so which now releases no power. Mini cooper advisors as the part was worn out that its not their responsibility which is untrue as it was in the workshop which is not my fault as incident has not occured while in my care but in the care of AURIC AUTO.so how does this become my responsibility or my fault if it wasnt in my care the time this has occurred? ????