Be careful, this is a rogue casino.
Last year I deposited 200 usdt which turned into 2100 after a month. I went through verification and tried to withdraw my money, but they always reject my requests, except the last one which they can't process for over a year now. Now I found out that they just confiscated my entire balance.
kyc email -

some betting history -

last withdrawal request(in russian) -

current balance of my account -

First they asked me to verify my account (I didn't save this chat), and after verification they only replied to me once with a useless reply

Quoted your post for images visibility.
It really looks strange the way they handle your complaint, usually the casino reject the users' withdrawal when they didn't have verified their accounts, but since you've verified your account, I don't see any reason why they reject your withdrawal. If they have completed your identity, they've done investigated your account.
Since you're a victim, you can create type 3 flags on the representative account.