Hi guys, got a Xperia xz1 g8341 on US Verizon network I've tried to get it sim unlocked by two reputable unlocking sites but they can't unlock it because the imie although valid has no data?? But one site did mention the only way to get it unlocked is by using a local phone repair shop to do it as they use a certain cable to Overwrite the Firmware, does anyone know what this cable is, cheers guys.