It is a not a complex system. This is what you and I know. ERC 20 network, Bep 20 network, Polygon network have the same address. Money sent into any of these address is easily accessible to the casino owners. Reputable casino's will help the customer to transfer the deposit to the right network. I have made this mistake once when trying to review a casino and later on talk to the support team, they fixed it for me. However some casino's will try not to sort out the issues for you. They just want your money and by law the sender is at fault.