It is not suggested to keep or store your coins on any exchanges sir. They might shutdown their platform at any time and your coin is at risk. Its better to keep your coins or tokens on a wallet were you have the control for the private key.
you are absolutely right .I have faced the situation when I was unable to sell my holding at zebpay .because their app was not working properly and the price of BTC was going down .It was panic situation for me.