It is a discriminatory practice for a person, or for two or more persons to conspire, (1) to retaliate or discriminate against a person because he has opposed a discriminatory practice, or because he has made a charge, filed a complaint, testified, assisted, or participated in an investigation, proceeding, or hearing under this act;
(2) to aid, abet, incite, or coerce a person to engage in a discriminatory practice;
(3) willfully to interfere with the performance of a duty or the exercise of a power by the Commission or one of its members or representatives; or (4) willfully to obstruct or prevent a person from complying with the provisions of this act or an order issued thereunder. Laws 1968, c. 388, § 601.