What I’m assuming is OP try to use different identity probably family member/close friend since the first KYC was failed while the account itself still no registered name under it. Maybe if your support try to help him by clarifying why his first KYC failed then he can just repeat the process.
Not sure if this is the exact same thing that happened here as what I had in mind from my experience overseeing other casino's situation, since that case was about questionable KYC selfie, which roughly the same as what's being counter-accused to OP here.
But, and first thing first, the winning was being hold as the KYC verification process suggested that the account holder and controller are not the same as the one performing KYC. This lead to a strong possibility of a bought account. Though not explicitly mentioning a case of bought account, they actually covered this in there ToS,
By the terms agreed between OP and the casino, they actually have the rights to confiscate everything, even the amount deposited.
That said, second thing I'd like to address is what mahdirakib also brushed upon. OP, is there any reason why you need a very long time to do the second verification?
Normally, at least if I was in your shoes, upon being notified that my KYC failed to be verified and I was asked to re-perform it, even with my procrastination tendency, I'll do that by the weekend after I got notified, at the latest. So why wait that long?