How many codes did you get? I think I figured this out. You should have one for the PSN which is like 12 or 16 digits. Go on PSN and REDEEM your code. It should install the FF14 BETA INSTALLER. From there, log on to:
Whether you have a square-enix account, choose the option that fits you. From there, you enter your info and it should then ask you for your 20 Digit code. Put that in. I think I will send you to the SE account management and you click a icon on the left hand side (might be different, I used my phone first before switching to my computer) but you click services. Uh, can't remember what you do here, but once you put in the code and redeem it, go back to you PSN and click into the installer. Follow the direction and link up your account to you PSN account and it should download within the next 2 hrs. I hope this helps. I know I'm missing alittle info. Let me see if I can find if for you.