Have you done all of the following things?
- Got the Gamestop Keldeo in Pokemon Black/White.
- Traded it over to Black/White 2.
- Taught it Secret Sword via Move Tutor in Black/White 2.
- Went to the place I told you in your last question.
- Interacted with the Keldeo.
Theses are the steps to get Keldeo, I have got it by doing all of this.
Oh yes, and its Super Awesome!
Read more here.
Read this too.