Start by checking your internet connection, as it has to be stable for newly purchased items to be added to the game. If the connection was lost during or right after the purchase, try restarting your device and check to see if the purchase shows up.
If the purchase still doesn't appear in the game, contact our customer support. Make sure to provide the following information about your purchase:
1. The exact amount of the items you purchased.
2. The approximate time of your purchase.
3. A copy of the receipt or a screenshot of your purchase history. The receipt is emailed to the account used to make the purchase soon after the purchase is completed. You can find more information about your purchase history in the customer support section on the Google website.
More information can be found here: