My new iPhone 5 won't let me send or receive texts or emails, and it drops phone calls when I'm at a friend's nearby apartment. My apps are all closed, I'm not on wi-fi. I called Customer Service, and they said to be sure that - in this setting - my 'Settings' + 'General' + 'Cellular' + 'Cellular Data' is on, because my iPhone is probably busy looking for a wi-fi connection, and that I need to re-route the search to the Cellular Data. I've tried all that but am still having the same problems. Any thoughts, anyone?