There is a chance that you have been "blacklisted". This means that no bets or wagers will be accepted from you or your account anymore. If you have had credit card issues in the past with a site, then they may blacklist you and not allow you to play so as to avoid future (and costly) issues with you. Another reason is that many gamblers will try to dispute charges or say that their card was stolen to recoup lost money. This is illegal, but happens. In order to avoid further loses, the casino will blacklist.