Since the application is sold via iTunes, it can be refunded via iTunes only.
How to get refund from the App Store via iTunes on Mac or PC:
- Open up Your Account in iTunes. It's in the top right corner.
- Once you're logged in, click "See All" under Purchase History
- Scroll down until you see the big button that says "Report a Problem". Click that big button.
- Find the app you want to refund and select 'Report a Problem'
- Choose the problem you're having and write a detailed reason why you think you should get a refund for the app.
You can also request a refund using any web browser:
- Go to Apple's problem reports page: http://reportaproblem.apple.com/
- Login with your Apple ID and password.
- Select the Apps tab.
- Find the purchase you want refunded.
- Select "Report a Problem" to the right of the purchase.
- Select the reason you want the refund.
- Fill in the description and select "Submit".
iTunes and App Store refunds typically take a day or two to process and you might get contacted by Apple support to verify the reason for the request.