OP could reply these questions here if he's clean or not since most casinos that are already here has a long history to tell and the amount we are talking about here isn't too big just to cause enough trouble, yet OP couldn't answer.

We really need the OP's explanation here since we are committed to know the truth of what was actually happening but if OP couldn't answer or tell us something then the side of the casino the truth.

Sometimes businesses have the right to change the rules of winning but if this was the casino's fault, then I think there's a misunderstanding that should be fix by calm communication since the amount involved isn't just worth the trouble.