once deleted, it is gone.... sorry for your loss
You can actually get a deleted alias restored ONCE, as long as you get an agent who knows the escalation procedure. They'll have to send the ticket to another department, and it will take 24-48 hours, but it *can* be done. I believe it's the "OSC" department that actually does the restoral.
Don't forget that you can always ask for a supervisor!
Do you mean sub account by an e-mail alias?
E-mail alias is like a nick name for your e-mail address. If that got deleted, your e-mail account is still there.