The commission may refuse to examine an applicant, or after examination to certify as eligible one, who is found to lack any of the established preliminary requirements for the examination or position for which he applies; or who is physically so disabled as to be rendered unfit for the performance of the duties of the position desired; or who is addicted to the habitual use of intoxicating liquors or drugs; or who has been guilty of any crime or of infamous or notoriously disgraceful conduct; or who has been dismissed from public service for delinquency or misconduct; or who has made a false statement of any material fact, or practiced or attempted to practice any deception or fraud, in his application, in any such examination, or in securing his eligibility; or who refuses to comply with the rules and regulations of the commission.

If any applicant feels aggrieved by the action of the commission in refusing to examine him, or after an examination in refusing to certify him as an eligible, the commission shall, at the request of such applicant, appoint a date, time and place for a public hearing; at which time such applicant may appear, by himself or counsel, or both, and the commission shall then review its refusal to make such examination or certification, and testimony shall be taken. The commission shall subpoena, at the expense of the applicant, any competent witnesses requested by him. After such review, the commission shall file in its records the testimony taken, and shall again make a decision, which decision shall be final and not subject to judicial review, but under no circumstances shall the provisions of this article be construed, in the case of a refusal to examine an applicant for promotion or to certify an applicant as eligible for promotion, as depriving such applicant of his right to seek a writ of mandamus, if the application for such writ is made within twenty days from the date of the decision refusing to examine or to certify him as eligible for promotion.