I have been answering 2 support tickets for more than two months.
They allow the purchase in btc of COX and do not allow the sale when they can not be moved to another exchange. Yobit is stealing user's coin in that way and it's not the only currency they use to cheat. BEWARE THIS IS A SCAM
There are already a lot of post about unfunctional support or withdrawal in Yobits here in the forum. You should have done your research first before you have engaged with them. Anyway, sometimes they still answer support tickets but really takes a long time. And some times they fix problems on coins without you knowing. You should check the status of the wallet of the coin in yobit before doing a transaction.