So it is safe to say that your account has been locked, since you cannot withdraw, deposit or do anything at all and when you contacted support, they didn't give you any reason why your account was locked and asked you to complete KYC, which you did. But you cannot still withdraw.

I would like to know, was your account restricted immediately after a big win which you tried to withdraw? Because that is something i noticed that a lot of casinos do these days. In addition to all the suggestions you have received, i will tag @Holydarkness here, let us see if he can be of some help to you.