Terrible company, terrible service

Took my car for a downpipe and tune and when I asked for my original catalytic converter there was hesitance to hand it over, only to find 2 days later the catalytic material was removed. They told me it came out of my car like that. This is a 60,000km car with full service history from the dealership. The material is expensive and is normally sold. I contacted them regarding this. Initially was told they will make it right and then was given the run around for 3 weeks until no replies came. Terrible service and would not recommend.