Here's what I did last night.

1) Go to the digital river site : https://www.findmyorder.com/sstore?A...r&Locale=en_US

2) Enter your info to pull up your order.

3) Then you should see a 20 character "Serial Number" in the following format xxxx-xxxx-xxxx-xxxx-xxxx.

4) Then go to Mog Station

5) In Mog Station you should see an option to "Add Platform". It's a square button with a flaming circle and plus sign. Enter your code here.

6) After you save and what not it should take you back to the first screen and you'll see 30 days were added to your account plus you'll see the bonus items listed.

7) Logged into the game (eventually) and saw the items in my mail.

Now, this is what worked for me. They might have changed it since then but poke around a bit and you might get it. Good luck.