Mentally Harassment By boss without any reason

Hi Sir , i am working in a company in which my boss is harassing some employees .Actually sir the matter is this on 27th Jan there was an party in my office and we did not get any official notification regarding the get together party and some employee left the office after completing the shift timing( 9am -6pm) .After some time my boss sent an official mail was saying that , Hi Team, Everyone will be doing 9AM -7PM shift till Boss is in. This has to be followed strictly by everyone. @ HR- In case there is anyone who does not adhere to the shared information, ask for resignation We had arranged today's office gathering keeping Customer Support in mind as they presence is as important as others in the organisation. As these people do not want to be a part of the organisation, then there is no support from our end as well @ Account - Salary of these people will be processed on 15th Jan 2018 and Overtime for the month of Dec 2017 will not be given @ Team members (only if you people understand what is a team) - Either we work together or we dont... Those who dont think working and staying as a team is important are pleased to walk away. There will be no concession for anyone. Kindly suggest us any solution as we are completely fade up .