First of all, you need to read terms and conditions of this casino carefully. See whether these rules have been changed lately. The last date of changing is normally indicated in the top or bottom line of the page. If you did violate the rules, your winnings should be cancelled and they will pay you out the initial deposit only. Sometimes, casinos do not want to pay out the initial deposit either. So, you need to create the theme about this fact on forums and walls to warn other players about it. If you didn’t violate any rules, this step is still more reasonable.