You can attempt giving it a hard reset (doesn't get rid of any files at all, I've performed them multiple times) by pressing and holding the home and power button at the same time until the phone restarts, or you could do a software reset. For information on a software reset, go to Apple's website, for information. Or, just go to Apple's website and contact them; they can have an employee (not a robot) chat with you live on the internet.
