I have had somewhat similar problems with band agents, guitar shop dealers etc etc in the past regarding $$$ issues. I can tell you it's very difficult to get your $$$ back though I did manage for certain cases by going through legal methods (laywers & even small claims court) but even that too it too quite a while.
Police report would be for normally cheating / cpib cases but doubt you all can get $$$ back, this would however generally cause problems for the individual though.
My 2 cents