My apple id was taken over by someone in Japan who started purchasing things on 9/10/20. I cannot seem to change back my info to United States. I did delete their devices off my account and change my password and apple id email.

My apple id was taken over by someone in Japan who started purchasing things on 9/10/20. I cannot seem to change back my info to United States. I did delete their devices off my account and change my password and apple id email. BUt how can I remove their country? These directions did not work:

From your Apple ID account page

1. Sign in to your Apple ID account page. 
2. Scroll to the Account section, then click Edit. 
3. From the Country/Region menu, select your new country or region.
4. When asked if you want to change your country or region, click "Continue to update." 
5. Enter your new payment information and your billing address, then click Save. You have to enter a valid payment method for your new country or region.1