If you encounter an issue, please send a support request to firstname.lastname@example.org.
If you think that there is a missing feature, share your suggestion on our customer feedback website.
If you still want a refund, you will have to contact Microsoft Store Support which handle the money transactions and they will handle the refund.
You need to contact their Answer Desk, here a direct link:
Then go to Billing, connect with your Microsoft account and write your request, then they will get back to you.