What happen to the OP..?
There's no clear picture and details of this certain site, OP is not active anymore too, maybe they are not serious in running their business here, because if they are they will take care of the very important details.
They are not active even on all there social media account. There website is not updated anymore and looks like don't have a regular maintenance. The casino is either dying or abandoned already by the owner after crypto currency market price surge since Q4 last year. Maybe the owner decided to cashout all his cryptocurrency instead on continuing this business.
Looks like it, I was about to suggest contacting them on Telegram but all I've got is a Slotman Bot and it is not even on English but rather a Russian language bot. It also doesn't include any commands on it.
It might be that the team that handle this website is already gone and/or planning to abandon it due to having less traffic and players.
The support may also just be a bot since it always replies on a same pattern of "Welcome to Slotman! Please note, that your account is at the verification stage. If additional information is required, the security department will contact you. Please, wait." just as asayoyaasa.
I'm sorry for you're loss but I think that your chances of retrieving your funds is too slim right now.