Kamonwan, after reviewing the circumstances of your case, we determined that issuing you a refund for your unintentional purchase is an appropriate exception to the iTunes Store Terms and Conditions, which state that all sales are final. In ten business days, a credit of 71.70 USD should be posted to the credit card that appears on the receipt for that purchase. If you have not received credited amount after ten business days, I would suggest you to contact your financial institution.