Get a Replacement from Apple
In these cases, thieves damage your iPhone, like cracking the screen, for example. Then they use the ID numbers on the back of the iPhone or in the SIM tray to contact Apple and ask for a replacement iPhone. This doesn’t usually work, because Apple customer service and Apple Stores generally require more information, but if you have an AppleCare+ plan it may be activated to send a replacement under the Express Replacement Service, which does not require you to send in your iPhone ahead of time. All of this is a lot easier if the thieves know your name and other personal information.