Yes, what's the name of the mission? Was it single- or multiplayer?
No mission gets deleted without it being against our submission rules or unplayable. And even still, we always send e-mail or an IM to the author first asking him to fix the submission.
So, if you haven't received this kind of e-mail or IM, then there's a good chance your mission is still in the depot.. or something very mysterious has happened to it.