A. The commission, each commissioner and person employed by the commission may, at any time, inspect the accounts, books, papers and documents of any public service corporation, and any of such persons who are authorized to administer oaths may examine under oath any officer, agent or employee of such corporation in relation to the business and affairs of the corporation.
B. Any person other than a commissioner or an officer of the commission demanding such inspection shall produce under the hand and seal of the commission his authority to make the inspection.
C. A written record of such testimony or statement given under oath shall be made and filed with the commission.