How to attach my Apple ID to a different Apple Store (change country)

Hey everyone,

I few months back I moved from Brazil to France and I haven"t been able to change my Apple account to make it compatible with the French Apple Store.

I go to my "Account Settings", choose to "Change country or region" and choose France in the countries list, but when I click on "Save changes", I get back to my account summary and nothing has changed.

Has anyone ever succeeded to change their country information? How can I do it? All my devices are synced with my Apple ID, I don't want to erase it and create another one if that can be prevented.

Thanks!