I recently called Sony as to the problem of why we cannot use our codes as it keeps saying Invalid/Already used and/or An issue has occurred, and the response was, the reason it says that is because the PSN is yet to update to register FFXIV in their system, regardless if you pre-ordered or bought it early.

We, unfortunately have to wait until 5pm PST (which I was told by C. Service) for the store to update.

So if you called for the day off, well, sucks for you.