Does Avis drivers take the items left behind in the vehicle

My question is, does Avis drivers take the items left behind in the vehicle. I had a terrible experience with Avis, from booking to executing. It is so difficult to speak to a consultant, I am being transferred from one to another and never get to speak to the same consultant. I left an item of sentimental value behind upon returning the vehicle. Bringing this to attention, it took the consultant seven days to get back to me and was just very neverminded, stating that there was nothing in the vehicle. I am very disappointed in the service.