Dragon Nest JP

If I recall correctly, the sareteiru part of that is keigo for shteiru so that means "You are already registered" not "The registrations are already done". To even make that part grammatically correct for "The registrations are already done", it would absolutely have to be　既に応募がされています. The ga particle is that important.

If it was closed, they'd say something more like "応募は既に終了いたしました"

The first time I clicked the apply button, i did not get that message. But the second time, I did.

I'm going to check out their blog now.

My bad. Guess my browser didn't feel like loading the page when I tried because I only got that message.