Allright I finally got my authorization... but only for the return!
I messed up filling the form with a not operating date flight and Delta didn't issued the authorization asking me to send another form with correct date. Bummer...
Delta staff in CDG had told me last week not to worry about the date since they make an OPEN reservation and when I come to Delta counter to issue the ticket I choose the correct flight and date.
Let's hope them to be a little faster this time since departure's due next Wednesday.