I redeemed a digital copy, now i can't find it. Code says redeemed by iTunes.

Does it appear in the Purchased area of the iTunes Store when you're signed into the account through which you redeemed the code?

I have the same exact question. Just got a blu-ray and did the necessary steps to get the digital copy. It shows up in my purchases at the itunes store, but it is found nowhere in my library or my computer. Is there a way I can re-download it? Even when I hit the download symbol to check for new downloads, it doesn't show up there either.

Try going into preferences (iTunes menu -> Preferences...) and enable "Show iTunes in the Cloud purchases". The movie should then show up in your movie list with a cloud icon you can use to download it.

Alternately, you can go into the "iTunes Store" section, then click the "Account" quick link on the left and see if the resulting page displays "You have XX items awaiting download" along with a button you can click to download them.

This solved my issue, thanks a lot man!