So this means that duelbits is not banned in your country but gambling is not allowed in your local country and hence ISP block the gambling sites and you need to use VPN to access the site. In that case, there will be no issue from the gambling site but if somehow ISP comes to know that you are still playing gambling, maybe they can take legal action against you    Anyways , duelbits have nothing to do with it and they will have no objection over your playing gambling through vpn.