battlefrony activation code already when trying to install game

hi

I have attempted in install battlefront from dvd on my machine , on the first attempt I entered my activation code and the install began and failed ( stating that I can reinstall or redownload)

When trying to reinstall it fails stating the code is already used , but the game does not show up in the list of games I own, .... please assist as I am really keen on playing this game

thanks