I think this kind of scenario is educational for us so that we won't do what you have done so far. I mean, that's kind of distressful, especially you didn't do anything stupid. You just simply put all your bitcoins into their exchange and you want to convert it into fiat but they hold your coins instead. The worse scenario with this is, they will let you do what you want with your bitcoins when the ATH has already done. That's kinda ridiculous.