change of country

In order to change country you will need to fulfill certain requirements as stated here

• Spend any balance remaining on your Apple ID. If you're not sure whether you have a balance, check your Apple Account balance.
• Cancel your subscriptions and wait until the end of the subscription period. 
• Wait for any memberships, pre-orders, movie rentals, or Season Passes to complete, and wait for any pending store credit refunds to process. You can cancel a pre-order.
• Make sure that you have a payment method for your new country or region. See what payment methods you can use.
• Redownload your apps, music, movies, TV shows, and books on any devices that you might use to play or read them in the future. Some types of content might not be available in your new country or region. Learn what types of content and services are available in your new country or region.

Make sure that you have fulfilled all of this requirements and after that try to change again

Hello ~In addition to the excellent post by * WheelieNick * …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~