
It's been more than 1 month that I've been waiting for my cashout...
Have you tried to contact the support through the chat window at bottom right corner? What is their explanation to your issue?
Also, if the support can't solve your problem and give a reasonable reason, I would suggest you to create a thread in 
https://bitcointalk.org/index.php?board=83.0 to warn the others about the problem.
OP is very inactive here and only come by once a month, but I guess there is no harm sending him a PM as well.
There are many other players complaining the same issue on the chat box, but seems that the admin/mod is not really active just like in this forum.
Their twitter account 
@win88casino, their last tweet was 7hours ago, but I could not find any tweets regarding to their withdrawal issues, most of their tweets were only about their account stats "follower and unfollower stats" LOL
One other weird thing is that I got this when I clicked the HELP & FAQ button. What does it mean?

And yeah, if he has tried to contact their support but get no answer for so long time, its better to create a scam accusation thread. 
But he need to provide as many as valid proof as possible.