I think OP need to run a check to detect the major cause to that challenges he's facing and am sure it's from his own end, i have an account with Gamdom and I never had an experience of such while opening my account, infact their site is one of the best most recommended casino when it comes to ease of creating an account for nee users, how do you expect them to get much player if their registration procedures isn't that easy.
I think it's natural that someone can't register at one or more gambling sites because not all casinos can permit that person to register and play gambling there. In this case, I don't think he should try other methods because we don't know whether they will violate their rules or not. After all, the rules of the casino can also change at any time. Connections, caches, or even restrictions from casinos for certain users to access their gambling sites will determine whether users can register or not. But to be clear, many other reputable casinos that @OP can use to sign up and play gambling and do not just stick to one reputation's casino.