OK guys, I got the fix! But you aren't gonna like it...

Basically we attached our Early Access code to the wrong account. Your P4 characters aren't gone, they are just on the account that is not activated (you can see them as your forum avatars).

A guildmate of mine just gave me another Early Access code, I attached it to the other account, logged in with that account and voila!...my level 20 P4 character is back!

So either:

1) get another code
2) submit a ticket to transfer your code (they will let you do this, but it could take days)
3) start a new character

Hope this helps and good luck!