How can I change the country? Eventhough I follow all the steps when I save it and log on again there is no change.

I have been leaving overseas and created an account in Australia. Now that I am back in Spain, I am trying to change the country to be able to use the spanish app store but I can not do it. I change the country and the credit card detail in my apple Id settings and save it. When I log on again there is no change.