Read this support article for full information about requirements for changing your Apple ID country or region --> Change your Apple ID country or region - Apple Support . Although it only mentions one way to empty account balance, there are actually three valid ways; all of them are part of official Apple Support documentation:
1) Spend it:
If your store credit is less than the cost of a single item and you still have a valid payment method such as a credit card for your old country, you can use the payment method to make up the difference in the cost of an item ( How apps, content, and subscriptions from Apple are billed - Apple Support ). Perhaps buy something such as a music track which you can download and also keep a backup copy. Remember that anything purchased may not be available for re-download in another country but as long as you have your own copy you will always have it.
2) Ask Apple to keep it:
You can use one of these methods to ask Apple to remove the balance and keep it:
● Click here --> Choose your country or region - Official Apple Support Select your country, then a product such as billing. If you do not see your country, see if there is an "other" listing for that region. If you don't see an option 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.
● Call Apple Support --> Contact Apple for support and service - Apple Support
● Click on this link and fill out the form if the above two contact options are not available --> Media Services - Contact Us - Official Apple Support
3) The article: Check your Apple Account balance - Apple Support has a section titled, "If you have an Apple Account balance that you can't use". You can ask for a refund, but only under very specific conditions and locations to the extent that I have yet to see anybody respond saying they have used this method.
In the interest of full disclosure of all ways available to you, the above is my usual list of ways to remove all account balance. Apparently despite the other methods all being present in Apple's own official documents, recent indicators show this more complete list apparently goes beyond what is considered to be a good response to your question. I invite you to see if any of the alternative methods may be available to you.
