Blacklisting is entirely different from carrier locks. When a device is blacklisted, that means it can't be activated on any carrier. More often than not, this means that your phone was reported stolen. If you did not initially purchase the phone, there isn't much you can do to get the phone activated. Even calling the original carrier who blacklisted the device likely won't help because it will appear to be someone else's stolen property. Contact the carrier you originally purchased the phone from if it's blacklisted. Based on experience, this can be a lengthy process that needs to be escalated several times. The Blacklist is supposed to be a permanent block, so be prepared to put some time into it.