Possible Solutions:

• Verify whether the purchase was made on a different console.
  • If a Nintendo Account has been linked to a Nintendo Network ID (NNID), the Nintendo eShop balance is shared between Nintendo Switch, Wii U, Nintendo 3DS, and off-device purchases through the Nintendo website. This means that funds added or spent on one system will be reflected on the others as well.
  • You can sign in to http://accounts.nintendo.com and check "Information About Account Activity" (in “Shop Menu”) for a record of all purchases made on or after 03/03/17.
  • Transactions made prior to 03/03/17 are located in the account activity on your Wii U console or Nintendo 3DS system.
• Verify which Nintendo Account the funds were added to.
  • Funds are not transferable and are not shared between different Nintendo Accounts.
  • Funds added to one Nintendo Account will only be available when signed in with that account.
  • If you have more than one Nintendo Account linked to your console, check the balance for each account to see if the funds were added to a different Nintendo Account than the one you were using.
• Make sure the funds were added for the same country/region that your Nintendo Account is set to.
  • Your Nintendo eShop account balance does not carry over if you change your Nintendo Account country/region setting.
  • If you have added funds while the Nintendo Account is set to one country/region, you will need to use the remaining funds before you can change the country/region setting.