Problem with redemption code

I´ve bought my Black ops 2 game 5 days ago. I am trying to enter the code to unlock the NUKETOWN 2025 map and it doesn´t work, ¿does anybody knows what´s the problem? The Black ops 2 package was openede by me, no one used the code before. I´ve entered the code with dashes and it doesn´t work. I am from Argentina.

Thanks