"your account is not valid for use in" even after I changed the app store country

I changed the iTunes/Appstore country from U.S. to China. But I still can't download apps in the store I changed to. It says "your account is not valid for use in the Chinese store. you must switch to the U.S store before purchasing". Then I changed the region in Setting - General to China as well. But I still can't download. Then in Appstore I signed out and signed in my apple ID. Then the store changed back to U.S.