Sorry to hear that.
Unfortunately, in the United States at least, there is no blacklist per se between carriers since we have the idiotic patchwork of networks/technologies. Too much of the 'wild west/we do it better than everyone else' mentality here to see the logic of having everything on one single system <sigh>.
OTOH, it's a hybrid device, being the Sprint/CDMA version of the iPhone. AFAIK Verizon won't allow it on their network, nor will Sprint if they don't change the device ID in a way that cloaks it from Sprint.
My phone got stolen last week. I just wanted to know does the serial numbers of phones get reported to other cell phone companies. I had an Sprint iPhone 5. They reported to my account but I know people can still change everything.