I bought some golds through the Steam, and I received my receipt, but I haven't get the gold still now, it's a week already. Here's some details.

Your recent in-game purchase through Navy Field 2 : Conqueror of the Ocean has been processed and 21.00 GBP has been debited from your Steam Wallet.

This email message will serve as your receipt. You can also access your Purchase History online at any time.