In order to issue a refund or send you missing items we need your Google Play Order Number. After you buy something on the Google Store, you’ll get a confirmation email that you can use as a receipt. You can find your order number on this receipt.
If you can’t find your confirmation email, you can get a receipt online:
Visit pay.google.com/ and sign in with your Google account.
On the left, click Subscriptions and services.
Click View purchases.
Select an order to see your receipt.
If you need your order number, you can find it on the receipt page.