I am surprised that people are using VPN while duelbits clearly states in their term of services (https://duelbits.com/tos) that you cannot or should not access their service from a banned region. So if anyone is using VPN from a banned region, he may lose his account and funds, if got caught, so be careful.
I believe, the phrase that you've quoted from Duelbits' TOS, in general, it only applies for those people that really came from banned countries of their business. Not those who use VPN just to access other providers. Correct me if I'm wrong.
You are correct, the ToS clearly stated that they are forbidding the use of VPN for that specific scenario and not the VPN itself because that’s a clear violation of law which there license won’t allow. The VPN itself is not bad or against the law, It’s like a gun, It’s not good or bad but the purpose of its usage determines whether it’s good or bad.