Not running the task (Fallout Shelter)

Not performed the task in a fallout shelter to kill 12 krotokrysov bare hands. At first I thought it may not run due to the fact that when attacking kratocracy then it start to shoot first since I have the room all with guns, but then when kratocracy attacked an empty room I immediately disarmed the two residents and sent them to the room where kratocracy and still the task is not performed needs help to delete the job not because I want the reward for her carriage with the pet.