If, after notice and public hearing, the commissioner determines under reasonable assumptions that a premium rate charged for the insurance coverage offered under this chapter or the plan for operating and marketing that insurance is excessive, inadequate, or contrary to the public interest or that any activity or practice performed in connection with the insurance is unfair, unreasonable, or contrary to the public interest, the commissioner shall:
(1) enter an order containing the commissioner's determination and disapproving the premium rate or plan or the activity or practice; and
(2) require the discontinuance of the premium rate, plan, activity, or practice within a period that is not less than 30 days after the date of the commissioner's order containing the determination.