The attorney general may, upon the attorney general’s own motion, and shall, upon the verified complaint in writing of any person setting forth facts which, if proven, would constitute grounds for refusal, suspension, or revocation, as herein set forth, investigate the actions of any person holding or claiming to hold a license. The attorney general shall, before refusing to issue, suspending, or revoking any license, at least ten days prior to the date set for the hearing notify in writing the applicant or holder of such license of any charges made and shall afford such accused person an opportunity to be heard in person or by counsel in reference thereto. Such written notice may be served by delivery of the same personally to the accused person, or by    mailing the same by registered mail to the place of business last theretofore specified by the accused person in the person’s last notification to the attorney general. At the time and place fixed in the notice, the attorney general shall proceed to hearing of the charges and both the accused person and the complainant must be accorded ample opportunity to present in person or by counsel such statements, testimony, evidence, and argument as may be pertinent to the charges or to any defense thereto. The attorney general may continue such hearing from time to time.