how to fix store region error even if region is correct (not administrator added account)

Try going to http://commerce.microsoft.com to make sure your address information is correct. With region locked content, it's not the language that is the issue, but your actual
physical and account region. Both have to match in order to download region locked content.If that is all correct and it still won't work, try migrating your account region.

http://live.xbox.com/accountmigration For some reason on some accounts the 360 store will see you as being in a different region even if your account shows the right one so it'll give an error.

correct however the paypal's account region must match the region of your xbox live account to be added

Goto billing.microsoft.com

A region cannot be changed once set

All the family accounts must be in the same region to be added

You will have to create a new account for the correct region if one isn't in the same region

HI I bought game in Denmark, my region is Denmark so how is possible that game is region locked.

To which region ? why i can bought i game not working in the region where was bought ?

It's best to create your own thread in order to receive proper assistance. The game is available in Denmark so as long as your account region matches your location you should have no issues with it. If you are getting the same error message as in the original
post or an error code like XBOS-3012, you'll want to go to
http://commerce.microsoft.com to make sure your account information is correct and try re-entering your information even if it is correct. If you still get the error, you'll want to try migrating your account region - https://support.xbox.com/my-account/microsoft-account/update-microsoft-account-country-region

True dat. When a few regions were added last year a tool was added for people in those countries to migrate their accounts to the correct region. A lot of people were stealing accounts and then migrating them to those regions under the impression that the
original owner wouldn't be able to get the account back.