So, you already receive the 15k deposits and they reopen your account? But you have still balance (winnings) 15k there right? And your account was closed back?

As for the giving more explanations, i guess casinos have the same behaviour of not telling more, they only tell you, that "you violate our rules, we close your account and don't come back" lol. It's unfair and unjust.

As for the reason, I only guess is because of your transaction of 10k deposits and 10k withdrawals as it looks like you're making the casino as a mixer to launder your money, that's just assumptions though. But if they allowed you to refund your deposits, then it doesn't make sense regarding the assumptions of "mixer" money laundering since most casinos are strict related to AML.