Has anyone met with a similar incident?

While returning the car to AKL Airport, I left my sunglasses and GPS Suction cap in the car.

When i remembered, i walked back to the Avis Counter to get the keys, they said the drivers took it back to the service centre.

Then i emailed Avis NZ, and they say nothing was reported.

Its the span of 10 minutes which i don't understand. If such thing is happening, it just shows how clean their hands are.