As payments on our games are processed through iTunes, Facebook, or Google Play, your purchase history can be viewed through them as well.

Open iTunes on your computer.
Select your username (this should be your e-mail address), and choose “Account”
Scroll down to “Purchase History”, and choose “See All”

Click in the top right of Facebook and select Settings.
Click Payments in the left menu.
Click a payment to see your receipts.

Google Play
Open Google Play on your computer.
On the left side of the page, click "Subscriptions and services".
In a section labeled "Other purchase activity", there should be a link labeled "VIEW PURCHASES", click to see your receipts.