Thank you for taking the time to post!
I will need some more details in order to investigate this further: Can you let me know if you are seeing a message when you enter the code? From which retailer did you purchase your Season pass? Are you connected on a wired or a wireless connection?
I brought mine Call of duty ghosts Harden Edition from a gaming retail shop in Hong Kong. Both of the code when entered show "The code you entered may not be correct or may no longer be valid." I am connected on wireless connection but I have try using playstation website to redeem my code and still not work. It is possible I could send atvi support photos of the codes and evidences.