LOST GOODS MISSING FROM CAR

I left by accident my GARMIN GPS in the MINI LEASED VEHICLE , ON RETURNING VEHICLE I PARKED THIS VEHICLE UNDER SECURITY CCTV CAMERA. SECURITY FAILED TO INSPECT CAR INTERIOR, DRIVER WHOM PARKED VEHICLE IN STORAGE AREA FAILED TO INSPECT INTERIOR. MY GARMIN WAS PLACED UNDER HAND BRAKE LEVER. I LEASED THIS CONTACT FOR 14 MONTHS. MY GARMIN IS MISSING AND I AM NOT A HAPPY CUSTOMER. THIS WAS REPORTED TO MR ENGELBRECHT AT HO, HELLOPETER AND TWICE ON AVIS COMPLAINTS AND NO JOY ON SOLVING MY PROBLEM