Section 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.