I found most service providers just want to sell you a new phone and aren't much help getting yours back. At least if you leave service on, you have a chance of finding it when the thief uses it. You can also check in your Google account from another device or PC and see the location of the devices you're signed into, unless they factory reset it first. It's a little risky depending on whether your phone is locked or they can unlock it, what they can get into, but if you choose to sign out and erase device, you'll have a harder time finding it. Even factory reset locks the phone to your Google account on some phones, unless you've signed out. Hope this helps!
