I have the same situation. Support is not responding. I think it has to do with smart contracts on ETH. Apparently YObit has not updated their ETH wallet and so they do not accept deposits with smart contracts.

All the deposits seem to be falling into this account https://etherscan.io/address/0xf5bec430576ff1b82e44ddb5a1c93f6f9d0884f3 someone is collection a nice nest egg.

My sum is not quite as high as yours but I would be really P@$%@$#%F if the would not release 15 ETH. I would spam the crap out of them.

Good luck.

ps: There seems to be a user dominikherzog that responded once to a previous support ticket of mine. He is active on the chats but does not seem to be looking at support tickets.