Hey there. welcome to our forums.
Sorry to hear you're running into this issue with your account region.
Unfortunately, your game account region is locked in as soon as the account is created and can’t be changed afterwards. The Webstore checks that region against your current connection, which is why that error pops up.
You can try contacting the Webstore team directly on the website to see if they can take a look, but if they aren't able to help, there isn’t really anything more we can do from our end either, as we can't manually override or update account regions.