Missing of USB

On Thursday 18 January 2018, I send my car for 90km service, upon collection of it i find that work USB which i hide it inside arm rest was missing. The manager and the sales representatives did try to assist as to who might saw it between service area or car wash area but both guys denies that they saw it. On the very same day the Manager calls the guy who managing the cameras so that he can check as to who really took it, unfortunately the was not available on the day but promise to come for the following day. He then promise me to give me feedback/ response on the camera footage outcome but till today I did not receive any call from him (Manager- I did not take his name)I am very hurt especially with work USB (8GB) which went missing during my car service and I would like to get feedback as to who took it and why because *****ing is not good especially in this kind of environment where the company is dealing with customers on a daily basis. (Disappointed)