i lost my safari icon for the longest time then one day I somehow got it back though I'm not quite sure how.
you may want to try this.got to settings> general> reset> reset all settings
not sure if that will fix things but its worth a try. it does reset your wallpaper and wi-fi so you need to type in your passcode if needed to connect to your wireless network. aside from that its doesn't mess up anything else I jsut tested it out and got a new itunes icon.