Joy riding customer’s cars

I dropped off my X5M for windscreen repair and it stayed over night ! When I collected it in the morning it seemed like the guys there were joyriding my car! I left the car there with 100km of petrol and only to collect it with on 40kms and the safety belts clipped on both driver and passenger ! Clearly someone was joyriding the car and they had the belts clipped behind them too. The belts and the petrol kms just sold it off !!