Can't reinstall Mass Effect 3

Login to Origin with the credentials you used when you first installed ME3, open "my games", set it to "show all games" and install ME3 from there. If you don't want to download ME3 entirely, you can use this guide to install the main game from disk.

Thanks for the speedy reply. I actually tried to go through origin. When I load it up, (credentials have not changed, only my onscreen name has since I had to reinstall Origin as well), it doesn't even list it. It lists BF2 Euro. I have NEVER played that game. Not sure why it would be on my list of "My Games".

  Is there a way I can get this game code released so that I can reuse it again. I can provide the code, as proof, that I have legitimately bought the game. I can also provide the last save file I had, just before I beat the game in my first play through.

Why did you have to change your onscreen name? If you re-install Origin, you login with the same name or e-mail address and password you used when you first installed ME3. If you install Origin and use another name, you create a second account that doesn't carry over the games from your old one.

In any case, if you still cannot access ME3, you'll have to contact official EA support here: https://help.ea.com/

I was not sure. When I reloaded Origin, I typed in my login name from before. However, it said that it was already in use. After trying to get it to work, looking around at the forums, I simply gave a new one.

Also, whom specifically would I contact? I have looked over that site and have found no direct email address for getting the redeemtion code reset.

After you've installed Origin you don't make a new User-name, you login with your old one, to identify your account...

The game is tied to your first account you set up with your old user-name, that's why it's in use. In order to access this account you don't use a new login, you use your old user-name and password.