either it's banned for one reason or another or you're looking in the wrong place or you've mistyped your cd key. Two of these should bring an error message and not move go to a different webpage.
1. In "Summary" scroll to near the bottom as that's where classic games are, do you have any games at all visible there?
2. After key has been enterred in "games & codes" -> "add a game key", what happens? Should it not accept it, you get a red message stating an error has occured.
It won't automatically put you into this screen after putting in your key, you do need to go to summary and find the game and click on it.