That's a security thing. When some douchebag steals a phone and the owner locks it before the original sim card is removed, it essentially bricks the phone. So quite obviously you have a stolen phone. Either you stole it, or you bought it from some street "vendor", knowing full well it was stolen.
Either way, get the fuck off Tom's Hardware asking stupid shit like this. You're a thief or at best an accessory to a thief and either way you've committed a crime. Take the phone to the nearest police station and ask them to look into it.