The exit announcement was issued one month prior to the closure date, which was 3 days ago. There were also repeated reminders as the final day approaches. You must have missed all of them.

If you have funds there, I hope it isn't much. You can still try to contact their support though and hope they will still cater you.

Although all exchanges have scam accusations, Graviex ran for 7 years. And they didn't just vanish into thin air without a word.