I need to change the region for my account because I couldn’t use my new Credit card from another region

Did you complete all the steps mentioned in this related article?

Change your Apple ID country or region - Apple Support

Only the official Apple Support can help to transfer the rest of you balance back to you.

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• If you still can't change your country or region, or you have less store credit than the cost of a single item, contact Apple Support.

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copied from: Change your Apple ID country or region - Apple Support