Why the account is frozen? There's a reason for it and usually they detected something unusual in your activity. So the solution for this is to send documents if they ask KYC. Since you're not the real owner of the account I don't think there's a chance for you to withdraw your money.
Actually it's not that easy, friend.
If an account is frozen due to an act that violates the rules fatally, the casino will not easily allow the account to be able to make withdrawals. Moreover, if what is being done is fraudulent, the casino will never open an account that has been frozen.
Maybe he should sort out what happened first before the casino can approve his withdrawal transaction.
I think you need to look at this case again. in the case of the OP's account being frozen with the reason that the casino asked for KYC and the problem is that the account is not his original account and when issuing documents to the casino it will obviously be problematic because the documents and the original account name are different, it violates casino rules.
so here it's not a problem that the OP broke the rules by fraud but the OP doesn't have the original account documents.
if i understand this issue it looks like the OP bought the account from one of the people he mentioned in this thread, so this issue will be resolved if the OP maybe ask the account seller for help to send KYC documents. but I think the seller will not want to do that.