The Department may investigate the actions of any applicant or of any person or persons holding or claiming to hold a license. The Department shall, before refusing to issue, to renew or discipline a license pursuant to Section 17, at least 30 days prior to the date set for the hearing, notify in writing the applicant for, or holder of, a license of the nature of the charges, that a hearing will be held on the date designated, and direct the applicant or licensee to file a written answer to the Board under oath within 20 days after the service of the notice and inform the applicant or licensee that failure to file an answer will result in default being taken against the applicant or licensee and that the license or certificate may be suspended, revoked, placed on probationary status, or other disciplinary action may be taken, including limiting the scope, nature or extent of practice, as the Director may deem proper. Written notice may be served by personal delivery or certified or registered mail to the respondent at the address of his last notification to the Department. In case the person fails to file an answer after receiving notice, his or her license or certificate may, in the discretion of the Department, be suspended, revoked, or placed on probationary status, or the Department may take whatever disciplinary action deemed proper, including limiting the scope, nature, or extent of the person’s practice or the imposition of a fine, without a hearing, if the act or acts charged constitute sufficient grounds for such action under this Act. At the time and place fixed in the notice, the Board shall proceed to hear the charges and the parties or their counsel shall be accorded ample opportunity to present such statements, testimony, evidence and argument as may be pertinent to the charges or to their defense. The Board may continue a hearing from time to time.