If an applicant's original application for license or registration or a licensee's/registrant's request for renewal of a license or registration is denied, he/she shall have 20 days from the date of denial to make a written request for a hearing. If so requested, the hearing will be granted and the provisions of the Administrative Procedure Act and this chapter with regard to a contested case shall apply. If the hearing is not requested within the 20 days, the denial is final.