Battlefield 2142 cd key

Hi, my name is Dayton DeVille. I am a huge fan of the old battlefield games. I really enjoyed Battlefield 2 and decided to purchase Battlefield 2142 from Amazon.com. I installed the game and attempted to create the account. But it said the CD Code had already been registered. Any assistance would be highly appreciated,

                                 Thank You

                                                    Dayton DeVille