CD Key already used

Please read below this on how to re obtain your code for your game.

Lost / broken disk but still have the serial code for the game: With your serial code, you are eligible for the download version of your game. You can download it through Origin and redeem your code. Instructions on how to do this can be found here: http://help.ea.com/en/article/redeem-your-serial-code-in-origin/ Make sure to uninstall the previous disc version and install the download version instead.

Finding the code on Origin: If you registered the game or bought it on Origin, the serial code can be found in the My Games tab on the Origin client. Download the client from here http://origin.com/download, log in with your data and go to the My Games tab. Hover over the game and find the "i". The product code listed there is your serial number (it can be different from your original one if the game was bought before Origin came out)

No access to the serial code: If you lost your serial code and don't have the game installed on an old computer, you need to contact Customer Support. They can be found here: https://help.ea.com/contact-us if you registered your game to your account, it should be easy to get the code. If not, they'll give you a new code if you can proof that you own the game. See this: http://help.ea.com/en/article/obtaining-a-replacement-registration-code/

Read more in this article on game code redemption: How To Redeem your serial codes in Origin