Have you tried reporting the fraud to the IRS yet? It will cost you nothing but the time required to download, fill out, and email the form.
http://blog.charitynavigator.org/201...ity-fraud.html
I fail to see how a charity can benefit from a raffle, including picking and announcing the winners and accepting the proceeds from the raffle, yet when a winner doesn't receive the prized turn around and claim that they weren't involved.