they are unreasonable not to give any proof they want to appropriate the money i deposited in the amount i won total 2,200$
There is no accusation against them so far but yours only. Maybe they are really that good and you really have cheated otherwise they won't just do this with just $2,200.
But yep you may try that ask gambler suggested above. That's one way to do it for you to be heard since they already stated it's final. They seem to be confident in their decision and there could be truth to what they are saying. Sorry for your loss.