Do not use yobit.net

Last night I bought ETZ from yobit.net at price around 200$ and then sold them at 294$ and the selling was done and the balance of my ETZ became zero. I am sure because I could not sell them again. but later I saw the ETZ coins are still in my wallet and not sold and the price was fallen down to 120$. this is a loss for me.
why this happens at this site? this is scam.
I think producers of this coin is the yobit or at least related to yobit. because the only exchange selling it soon after the fork was yobit and the price became high soo in this exchange and buying was possible but selling was not possible when the price was high and the site was hanging and not working properly when I tried to sell when price was high.
take care of this site and never use it.
use only reliable exchanges.
also I have sent some tickets to this site from one month ago but no reply I have received still.
what can I do?