I am sorry that you lost your money, and hopefully you will learn something from all of this. I have to agree with what Wapinter said that your coins should never have been left on a centralized exchange in the first place. If you had them in a personal wallet, you wouldn't have to worry about what happens to Decoin or any other site. Use this negative experience to learn about self-custody and how it can benefit you. Also, remember that an exchange is not a wallet for long-term crypto storage. It's just a temporary service you use to swap two coins.