Q: How am I charged for something I purchase within the game (In-App Commerce / microtransaction)? A: You are billed/charged the same way for any other purchase on your iPhone/iPod; through your iTunes account. If you have any billing disputes or questions, please contact Apple.
Q: I purchased something in-game, but I cannot see it. What happened? A: In some cases, you may need to exit the game and restart it to access your new content. If that doesn't work, try turning off your device and restarting it. You can always check what you've purchased by entering the game's portal (for example: for Sims 3, select 'The Sims Store' from the game's main menu, then select the 'My Stuff' folder in the lower left hand corner of the screen).
Q: I purchased something on my iPhone. Can I get this same content on my iPod (or vice-versa)? A: Yes, as long as those devices share the same iTunes account. You can always check what you've purchased by selecting the 'My Stuff' folder in the lower left hand corner of the screen.