If you or another person (such as a child or friend) has made an accidental monetary purchase through Google Play, we recommend contacting Google Play Customer Support for assistance. If they are unable to refund you and the purchase was made within the past 30 days, please send us a screenshot of your receipt. Please ensure that the receipt includes the following information: date of purchase, order number, and purchase name.
To prevent accidental purchases, open the Google Play Store app. Then, touch Menu > Settings. Under User controls, select the checkbox next to “Password - Use password” to restrict purchases.