When you make a purchase on Google Play, a confirmation email with your order information is sent to the Google Account you used. You can also find your order information on Google Wallet by following these steps: 
  • Visit Google Wallet to view your recent transactions at this link:  https://wallet.google.com/manage
  • Select an order to see your receipt.
If you have additional questions on how to locate your Google Play receipt, please refer to this link: https://support.google.com/googleplay/answer/2506346?hl=en

If you would like to contact Support for a purchase issue, please attach a screenshot of your receipt and ensure that the time and date of purchase is visible.

If you need help taking a screenshot from your device, here is a link with instructions on how to do this: https://support.google.com/android/answer/9075928?hl=en