Unable to download apps - Country/Region Issue
Hello
I have just started having a problem with my iPhone 5s in which I am unable to download any apps on the app store.
The message that appears says: "Account Not in this Store - Your account is not valid for use in the U.S Store. You must switch to the U.K store before purchasing".
The store changed to U.S a while ago when i tried to download and app that was only available in the U.S. A prompt appeared on screen asking if I wanted to switch (to which I said yes), but the download still didn't work and I have since been unable to switch back and therefore do anything on the app store.
However, when I go into settings > iTunes and app store > Apple ID, it states my Country/Region correctly as United Kingdom, although the box is greyed out and unable to be selected.
Any help would be greatly appreciated, thankyou in advance.
iPhone 5s, iOS 11