If the player plays in the casino and wins, they he should get paid, because it's casino's fault that they let him play there. If the player loses, they lost and there shouldn't be any refunds.
As long as you have a real chance to win in a casino and get paid in cases of winning, then there's no reason for refunds. There's another case when player plays in the casino, loses some money, then the player wins, the casino voids winnings because the player is from a restricted country, but the casino refuses to pay refunds at the same time. That's wrong, because in that case, the player played and spent money, but didn't have any real chance for winning. Then the player should get the money back.