Yikes. They even have a VIP account on the forum, and it looks like they are pretty big in the russian sector of bitcointalk and that is their main market where hey operate.
Have you tried threatening legal action? I am sure that you guys are in the right here, and there are definelty going to be scared if you threaten legal action. Have you found their company details, and do they have an address and a team behind the exchange?
I search they website. registered at UK.
But operate by Russian country.
i found some other exchange or review...
some people are complaint about they withdrawal is slow.
even they website mentioned 24 hours delay.
Imagine, withdrawal btc rate at 9,000..
delay for 24 hours.. rate dropped to 8,000..
Now even worst, delay 3 weeks.