Based on Punkz.com terms of service, it clearly states that players from restricted countries are not allowed to play at their casino. So even though it is technically possible to register and deposit without any block, that does not mean it is safe. If a player breaks this rule, Punkz.com has the right to take action based on the rules they already set.
So this is not just about a technical gap, there really is a valid reason the casino can use if a transaction related issue comes up. In the end the risk is carried by the player, not the casino.
That's quite classic that trying to break ToS will lead to very unhappy ending. Because when a person broke ToS of a company, he was at a disadvantage side but honestly I am not a lawyer to completely understand about it too well and accurately as how law enforcement will be applied with ToS and a website operation.
For example, if ToS does not allow people from a nation to join a site and use a service but the online site does not block and disallow that person in account registration, what will happen next?
Later, the site can terminate the user account but if it it pulled out after the user funded account, bet and won big, I am not sure how the user will lose this case and how the company can defend itself against any lawsuit from the user.
It's about law, and as said I am not an expert in this field, so as a normal user, not expertise in law, I would like to take care of my money by obeying to a service's ToS.