§ 43. Complaint handling procedures. 1. The commission shall maintain regulations for the handling of residential customer complaints, which at a minimum shall require that each utility or municipality: (a) maintain procedures for prompt investigation of any complaint on a bill for gas or electric service rendered or a deposit required and for prompt reporting to the complainant of the result of such investigation. If such report is made orally, the utility corporation or municipality shall offer the complainant upon a written request the opportunity to receive the report in writing; (b) inform any complainant whose complaint is resolved in favor of the utility corporation or municipality, in whole or in part, of the availability of the commission's complaint handling procedures; (c) refrain from terminating service for nonpayment so long as a complaint is pending before a utility, municipality or the commission and for fifteen days thereafter, or for such period as the commission for good cause shall establish; provided however, that as a condition of continued service during the pendency of any such dispute, a customer shall pay the undisputed portions of any bill for service including bills for current usage, or such amounts as the commission determines reasonably reflect the cost of usage to such customer; and (d) refrain from treating the disputed portion of any bill as late during the pendency of any complaint before the utility or municipality.

2. The commission shall maintain regulations for complaint handling procedures including complaints with respect to the negotiation of a deferred payment agreement which shall include, at a minimum: (a) provision for investigation and informal review and for appeal to the commission in its discretion; (b) that the burden of proof in all proceedings shall be on the utility corporation or municipality, except as otherwise provided by the commission for good cause; and (c) provision for parties to receive a written determination of any complaint, upon request, in plain and simple English, which determination shall set forth the relevant facts established, the reasons for the determination, what actions must be taken and what further procedures are available to a complainant.

3. The commission shall use its best efforts to complete its investigation and review and to issue, within ninety days, its final written determination of any appeal to it pursuant to this section.