Nullise the account balance

Hello ~If you are trying to zero your balance before changing regions…you may purchase an item from the App Store for more than your balance and the remainder will be billed to your credit card on file thus zeroing your balance . You may also go to lower left hand corner and click on Support and they can zero it for you or…

Contact Apple for support and service

Also if you are changing regions take a look through this article as well…

Change your Apple ID country or region - Apple Support

~Katana-San~

If you still have Apple Account balance left, which keeps you from changing the region for your Apple Account, you can either contact the official Apple Support about that and ask them to do that:

Contact Apple Support

Or spend the remaining balance to buy an app or content from Apple, which costs slightly more than the remaining Apple Account balance, so that your secondary payment method will be used to charge you for the rest of the payment.

If you haven't already, take a look at this article, to make sure you have completed all steps to be able to change the region successfully:

Change your Apple Account country or region - Apple Support

Welcome and thank you for reaching out. 🤗

Here at the Apple Support Community, we are volunteers (thoughtful Apple users) who share knowledge in an effort to help others, such as yourself.

We don’t have the power to look into accounts, make changes or remove the balance.

You will need to → Contact Apple Support to request a reset of your account balance to zero.

Thanks again for reaching out. 👍🏼

All the best! 👋🏼😉

Smiliñ 😎 Brian | Community Volunteer