How to set up a Help Ticket if you have a Nintendo eShop card with a scratched and unreadable code

If you have a Nintendo eShop card with a scratched and unreadable code, you can rest assured that there’s an official workaround by setting up a Help Ticket via the official Nintendo Support website, which can be accessed by clicking here. If you have multiple Nintendo Accounts (parent and child accounts) with your email address associated, be sure to specify which account was trying to redeem the card.

Source: Nintendo Support and Nintendo of America @NintendoAmerica