How can I refund the money I added to my Apple ID account?

You can’t transfer your Apple Account balance to another payment method. From the article below.

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 to request a refund. - When you contact Apple, please include the following information:

Your Apple ID.   -

The refund amount.

Your current shipping address.

Apple ID balance - View  *

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 - Check your Apple Account balance - Apple Support -->

"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."

A Community Specialist in this topic --> I made a deposit to my Apple account by m… - Apple Community recommends contacting Apple about your options:

Click here --> Choose your country or region - Official Apple Support Select your country, then a product. If you don't see one that handles your issue then keep experimenting with selections until you reach one that gets you a chat session or a telephone call and get the representative to redirect you.

or:

Contact Apple for support and service --> "See a list of Apple phone numbers around the world."

Click here --> Contact Apple for support and service - Apple Support

Contact Apple Support.

https://support.apple.com/contact