I am very sorry to hear this happened and it is terrible. Although your post does not describe the resolution you seek, you might want to call up the vet and discuss the situation and see if you can reach a resolution.
Since you voluntarily gave the xbox to him it is not really a police matter. You can probably file a small claims suit. You should contact your local clerk of court for information concerning the fees and procedure.
There are a lot of variables that go into answering this question. Provided you were let go due to no fault of your own, which seems to be the case, there are other qualifying factors you must meet - most notably minimum earnings during the qualification period.