Not happy with iTunes app purchase

Sorry to hear that. Now, what sort of help would you like from us, your fellow users?

By 'not happy' you mean ... ? Whether you might be able to get a refund or credit from iTunes Support depends upon the reason e.g. does the app not work as described, does it abend (have you tried deleting and redownloading it via the Purchased tab in the App Store app on your iPad and contacted the developer ?) ... ?

If it's not working as described or abends and the developer hasn't replied to you then follow the instructions on the page that you posted from for contacting iTunes Support or use http://reportaproblem.apple.com