Where do you get the card-jitsu cards on club penguin?

You have to go to WHSmith or some place like that and buy a pack of card jitsu cards and in that pack will be a code. Then you go on Club Penguin and go in the Dojo and click on your cards and then click 'add new cards' and it will say 'do you want to sign out and add new cards' click yes, and it will sign you out. You need to sign back in and then click 'unlock items online' and click 'i have got a code' then type in your code without the hyphens and click done.