The Commission shall maintain a record in each case which shall include: Pleadings, motions, intermediate and final rulings; Documentary evidence received or considered; A statement of matters officially noticed; Questions and offers of proof, objections, and final rulings on them; Proposed findings and exceptions; The final decision, opinion, or order issued as a result of the hearing; and A staff memorandum submitted to the Commission by any Commission employee. Oral proceedings shall be recorded by tape recorder or stenographer. A transcript of all or part of the oral proceedings shall be prepared upon the request of, and the advance payment of cost by, any party.