Hi there. Don't worry! Let's take a look and see what happened.

A)I've already paid and received a notice that the card was processed, as well as a Google receipt, however I still haven't received the item I purchased:

Please go to the Settings page on the Fortune City main menu and tap Restore Purchases. Look to see whether you have now received the item you purchased. If you still have not, please go to the Settings page on the Fortune City main menu and tap FAQ & Player Support to contact us. Be sure to attach your Google receipt (include an order number in the form: GPA.1234-1234-1234-12345) with your message to allow us to better assist you!

B) I've already paid and received a notice that the card was processed, however I haven't received a receipt from Google or the item I purchased:

Please go to Google Play and tap the menu icon > tap Account > tap Order history to see whether the item you purchased is listed. If it does not appear on the list, or if it is listed however you still have not received a receipt or the purchased item after more than 24 hours since the purchase date, please use this page to contact Google Customer Service.

What if you are an iOS user? Please then see this tutorial.