• In order to redeem a PSN key you can do it both Online and through your console.
• If you chose to activate the key through Playstation website then sign in to your account.
• Then click on your username and select “Redeem code” from the dropdown menu.
• Then paste your code in the designated area and redeem your code.
• If you chose to activate the key through your console then sign in to your PSN account.
• Go to the store page and go down to the bottom of the menu on the left.

Note: 

This product is not refundable or exchangeable.