You should continue advising whoever commits Munkar until you think that doing so alone is not enough. (Part No. 12; Page No. 347) Then you have to continue advising the person along with taking punitive action by referring the matter to the ruler or the authorities which are appointed for disciplining those who are perverted and disobedient.May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.