The association shall submit to the department a plan of operation and any amendments necessary or suitable to assure the fair, reasonable, and equitable administration of the association. The plan of operation and any amendments become effective upon the written approval of the director or his designee. If the association fails to submit suitable amendments to the plan, the director or his designee shall, after notice and hearing, adopt and promulgate reasonable amendments necessary or advisable to effectuate the provisions of this chapter.