How can I have my Apple ID balance refunded back to Apple Cash?

Normally once funds are in Apple Account balance the only way to get them out again is to spend them.

From: Check your Apple ID balance - https://support.apple.com/HT202359 -->

"About unused Apple ID balance

You can't redeem or return Apple Gift Cards, App Store & iTunes Gift Cards, or unused Apple ID balance for cash, except as required by law. If your jurisdiction allows for refund of redeemed gift balances, you can contact Apple Support."