I need help to empty App Store credit

You can't redeem or return Apple Gift Cards, App Store & iTunes Gift Cards, or unused Apple Account balance for cash, except as required by law. If your jurisdiction allows for refund of redeemed gift balances, you can contact Apple Support to request a refund. When you contact Apple, include the following information:

• Your Apple ID.
• The refund amount.
• Your current shipping address.

See Check your Apple Account balance - Apple Support.