If you would like a refund for an iTunes purchase, you have to request a refund from Apple. Apple handles all charges and refunds for our iOS users. We have no ability to charge your account or issue you a refund.
Please go to your original receipt and click "Report A Problem" and select the “request a refund” option.
If you don't have the receipt please follow the steps Apple outlines here - http://support.apple.com/kb/HT2727.