I hate to be victim-blaming with this kind of case, you just want to play but now you have $1500 and are confronted with the KYC, that $1500 is almost lost because of the violation of their TOS, casinos records everything time, IP address devices used there's a possibility that your mule's device and location will betray you, they know cheaters and how they worked that is why they have a strong warning they just don't put the warning in the TOS and hoping that their players will just follow.
Sometimes, we tend to break the TOS just to enjoy gambling despite the restrictions but as we take the risk, we should also keep in mind that our funds aren't in a safe place. 1500 is still a huge amount but to be honest, it would be hard for you to recover it. VPNs aren't that safe these days.
That's the thing, why would you need to break the TOS of the gambling platform especially that your money is involved. Maybe because of the thrill of not getting caught or probably that they also think that the gambling website isn't really strict with their rules. Even the OP said that he tried to access the website without using the VPN.
I suggest try other gambling platforms that is available for your country to avoid this kind of issue.
There are people who are really that stubborn when it comes to something on which even if they do know that it is prohibited or been restricted they would be always trying to push on even though its risky and on the time
they get caught then this is the time they do accuse out on sites that it is shady or they've been locked up as to know that they are the ones who did violate sites terms and conditions which it is normal for them
to make out such decision since its been always the rule.If you do violates then expect on what would be the consequences ahead and i dont think that you have the rights to make out some complaints.