The reality is this, if you have not located your phone by now, you can most likely kiss it good-by. Most thieves are well aware that when they steal an iPhone, to immediatelly turn the phone off...this defeats Find My Phone. Once off, they restore it as a new device in iTunes and slap it on eBay or Craigslist.
Change all the passwords you ever used on the phone: email, iTunes, etc. Report to the police & your carrier.
Normally, if you change your password, the saved password on device do not work anymore. (Well that's what the password is for)