Goods taken left in vehicle

When I returned the vehicle I was using, I left an item in the car. I then called the branch a few days later to find out if they have placed the item in their lost and found office. Firstly it took about 10 calls to speak to someone in the office and when I eventually got hold of someone I was promised a call back. This never happened. I decided to wait a couple of hours and when I called back, they said the person who I spoke to earlier was never in the office. The second person I spoke to promised to assist me and tried his best, however when a friend of mine went to collect the item I found that it was a replica of the item I left in the vehicle and my original one was missing. Can somebody assist me with a way forward in a case such as this.