Can't redeem my product key

I was trying to redeem a product code of some of my previous EA games but Origin is unable to redeem it. I tried the Battlefield Bad Company 2 key on Origin's website and it even accepted the key, after which it asked me to activate the regular BBC2 copy or the deluxe edition but after selecting either one, the site throws an error saying:

"We're sorry, this code cannot be redeemed here. Please redeem your code at the following site:https://activate.ea.com/applyentitlement.do. FAQ" 

I tried activating the copy on the aforementioned URL as well but the link does not accept the key.

I also want to know if I can redeem codes for other games like Medal of Honor: Airborne and Need For Speed: ProStreet. 

Thanks!