If you purchased items and don't see them in your game, try restarting your device, then running the app again and leaving it open for a minute.
Sometimes it can take a moment for the system to credit and give you your currency.
If you still haven’t received your currency after an hour or so, please contact us and let us know.
Please note: Our support team can only offer monetary refunds to those that made the purchase on Google Play. You'll need to provide us with your receipts and order number. You can find further information here: https://support.google.com/store/answer/6160235?hl=en-CA
As for Steam, and iOS, you'll need to contact them directly for refunds.
Please request a refund through iTunes. This may be done by clicking the "report a problem" link on your receipt or by navigating to account management in iTunes and clicking the 'report a problem' link there. Apple should handle the rest.
Please visit this page for the refund policy for Steam purchases: http://store.steampowered.com/steam_refunds/