Did you not redeem the code (install the game/use the code on Origin) before you lost it?
3 weeks is a long time to not install a brand new game 🙂
If you did install the game then your code is already assigned to your Origin account and you can find your code in Origin although you don't need it once you have redeemed it against your account.
Why would you throw away paper from your game box without reading it? What kind of a ramshackle life do you lead?
After you redeem the code, it can't ever be used again, so it doesn't matter...
