I copied this from another blog by Eddie Wong. Never knew about this myself.

The process for claiming a refund is easy, here are the steps:

1. Launch iTunes

2. Click on iTunes Store

3. Login to your iTunes account, if you’re already logged in click on your email in the upper right corner of iTunes

4. Click on “Purchase History”

5. Select the app that you want a refund for

6. Click on “Report a Problem”

7. Fill out the form detailing the problem with the app purchase and why you want a refund

8. Submit the problem report and wait for a response from Apple

The amount of time you have to wait varies, but it’s usually a pretty quick claims process.

Nice one Eddie.