I got an iPhone today and borrowed my dads credit card to sign up to iTunes and download the free Facebook app.

I haven't bought any credit for the phone yet (prepaid phone) but I can somehow use the app and view photos etc on Facebook.

Dad is having a minor heart attack that using the app will be charged to his credit card.
I called my service provider and they had no idea, he just said that it will eat my credit when I get it and kept repeating that iTunes charges for apps sometimes.

Why do I have the internet when I don't have credit or data? WiFi is definitely turned off.