Yobit is very famous for having no aid and help to their customers. They really have a poor support.
I know yobit exchange as an yoshit exchange, I am a user of it before and I do regret using it to be honest. One of the worst exchange imo
I have used them before but not with huge amounts. I just choose to trade and scalp there with any of my tokens long time ago that I do not need anymore and I dont find any value of holding for long.