If you cannot locate your purchase receipt, here’s an extended tutorial on where to find it, depending on the merchant used for your purchase.
 

Google Play (Android users, purchasing from a phone or Tablet)

 
Device:
  • On your mobile device, open the Google Play Store app. Tap Menu Account to locate your `Purchase History` section.
PC:
  • Visit http://wallet.google.com  and log in with the same account used to make your purchase with. All purchases should be listed under Transactions. Select the purchase which wasn’t received. 
     
    OR 
     
  • Visit http://payments.google.com  and log in with the same account used to make your purchase with. On the left, click ‘Subscriptions and services’ and then ’View purchase’. Select an order to see your receipt.
 
You may visit Google Play Support for more information: https://support.google.com/googleplay/answer/2850369?hl=en
 
An example of receipt:
 
 

Apple App store

 
Device:
  • Open your main settings and tap your Apple ID avatar. Click the `Media & Purchase` option and scroll down to locate the `Purchase History` section in order to display your purchase history and select the purchase which wasn’t received. 
PC:
  • On a computer with iTunes installed, click on ‘account email’ in the iTunes Store to access your account; you will be prompted to insert your Apple ID and password. Click 'Purchase History' to display your purchase history and select the purchase which wasn’t received. 
 
You may visit Apple Support for more information: https://support.apple.com/en-us/HT204088
 
An example of receipt:
 

 

Facebook (PC users, purchasing through Browsers)

  • While logged in, visit Facebook’s Purchase History. Select the transaction associated with your required receipt and be sure to click the price amount shown for the purchased item in order to view the full details of the receipt.
     
    OR
     
  • Provide us with the confirmation received via email associated with your Facebook’s account
 
 
An example of receipt:
 
 

Kindle Fire/Amazon Store

 
An example of receipt: