No oil in my cars engine!!!!

My car went in for a full service in January 2023. Since then everything seemed fine with the car. I have driven the car for +- 2000km after it being serviced. Less then 5 months later. Turns out there is no oil in the cars engine. My question to Hyundai Somerset West is: How come there is no oil in the car but I paid for oil when the car went in for a service?