Try logging out of your Highrise account, closing the application, and then logging back in. Usually, this will refresh your purchase and your gold will be delivered.
If this does not work for you, please send us a support message (you can do this by contacting us through FAQ in-game) with your iTunes or Google receipt. Your iTunes receipt should arrive in the email inbox associated with your iTunes or Google account within three days of your purchase. We will then review the receipt for validation and issue you the missing gold.