In order to help protect yourself from future unintended purchases, please secure your device from unauthorized use by implementing a password, PIN, or any other security lock. It is also prudent to change passwords for any linked accounts unauthorized users can possibly access, including your Facebook or Google Play accounts. 

In addition, we strongly encourage you to enable a password or authentication for in-app purchases directly on the Google Play app. You can find detailed information on how to set this up here: