Please confirm your payment with the following procedure when your in-app purchase didn't go through correctly;
 Log-in to Google Wallet(https://wallet.google.com/) with your Google account which is connected to the app
 Display the purchase history
 Check the purchase information on the list
If you were able to confirm your purchase, please turn OFF the power of your device once and turn it ON, then check the Multitasking before you restart the app.
The in-app purchase may take few