Thank you for using Apple Support Communities!
I was researching what might be going on, and found this article to try and help with getting your code redeemed.
iTunes Store: Resolving difficulties with redeeming gifts
- In your email application, find your music gift message.
- Right-click (or Control-click) the Redeem image and from the shortcut menu, choose Copy.
- Click in your web browser's address field and from the Edit menu, choose Paste. The web address should look similar to this: https://phobos.apple.com/WebObjects/MZFinance.woa/wa/com.apple.jingle
- Press Return. iTunes should open and accept the gift (you may need to login to your account).
If the above steps did not work, then try these steps:
- Locate your gift code. It appears after the "code=" text in the text you copied into the web address. In our example above, it would be RAAAAAAAAA3). Select and copy this code (you could also write it down).
- Open iTunes, go to the iTunes Store, and sign in to your account.
- In the QUICK LINKS section in the right column, click Redeem.
- In the resulting screen, paste or type in your code, click Submit, and your music will begin to download.
If that does not help resolve it, could you elaborate a bit on what exactly is not working?