Hello, my sister's iPhone 3G is having problems. Some of these problems include that it doesn't ring when she gets a text or call even when it's off vibrate and the volume is all the way up. She is still running iOS 3.x and doesn't want to restore or update. So, with this said do you think I should call Apple and possibly get a new one as she is still under warranty. She bought her phone from AT&T as a new phone in the original box on May 7, 2010. Thanks for your time and help.