Looks like i have company from Yobit, i had my worst experience by being a bad holder in one of the many scam coins in the exchange and then i have the worst user experience from Poloniex as i deposited my coins and it was not visible for almost three weeks and there was no response from the team till they sorted the issue.
@OP are these the chat from their customer support, it looks ridiculous.
It's really ridiculous, if he know the risks he should stay away from with it. And there many different exchange that you may choose, why would you not check the options? Every exchange site are have a problem sometimes but they find an solution to solve the problems.