I noticed that some people had this issue and I wasn't able to find a thread that addressed this issue however here are the details.

Bought a Digital Copy for the PC on the SE Store; Got the confimation email with the product code (XXXXXX-###-XXXXXX-###) then I went to redeem the code on http://preorder.na.finalfantasyxiv.com. I selected PC as my platform and after multiple hours of getting Error 3's the registration finally went through and I was issued a 12-digit PS3 Code. Now even if I try to resubmit the product code It kept returning the same PS3 code over and over. I really don't want to have to purchase another code from the store.

Thanks Kindly