Thread:Sannse/@comment-30443481-20161110180515/@comment-8-20161111172626

If you close an account, you can reopen it within the first 30 days.

If staff close an account, the person concerned can use Special:Contact to talk to us about it.

I will say though, that the most common reasons for accounts being closed is because the user isn't eligible for an account - which usually means they are underage. (That's not a comment on this case, I haven't looked into this specific situation)