The solution to your problem with another person is to treat them as a person. Sit down together and have an honest conversation. Engage on the issue head-on but don’t attack. Ask questions to learn what is going on. Don’t be afraid to express how you feel but do so in a considerate manner.
Trying to solve problems with people by instituting policies and penalties will not actually solve the problems. It may eliminate the symptoms in the short term but they will come back stronger in the future since the root problem was never resolved.
Honest, compassionate, caring conversation.