If you are looking for a refund for the purchase of this application, you must request this from the support web site for the itunes or app's store. You should note that officially the iTunes Store does not give refunds and that the terms of sale state that "all sales are final". You can ask, though, and perhaps they'll make an exception for you. Just state why you feel a refund is deserved.
iTunes Store - http://www.apple.com/support/itunes/contact/ - follow the onscreen instructions
App's Store - http://www.apple.com/support/mac/app-store/contact/ - follow the onscreen instructions