In terms of your actual options now, I would say you really only have 2:
* Crack the card out and submit it to PSA or SGC and have it re-graded. If they made a mistake on their end in the database and the card is real, you'll get it re-graded/re-holdered and it will have a legit serial number (hopefully) and if they somehow screw up again, you'll be able to show them how they did. If it comes back a fake, well, at least you know for sure
* Leave it as is and not know if it is real or not
Here is your scan compared to another one that sold on ebay a few weeks ago. I don't see any real red flags other than the darkness of the black color on the back, but that could just be the way it was scanned. I would just re-submit it for grading and see what happens. It is always possible something nefarious happened here, but my guess is that the serial number was inputted incorrectly in the PSA database.
