Sometimes it might take up to 4 hours for Facebook to process a transaction, but the vast majority of transactions are processed immediately.
More on this, on this link:
First, please refresh the game to check if you have received your items.
If you haven’t, please allow some time for the transaction to be complete. Once we get confirmation from Facebook, we instantly send you your premium items.
If a transaction appears as completed but still did not came through, please message us by clicking on the link from the header, and we’ll gladly assist you.
Don’t worry, we solve 100% of these rare instances! 🙂