(d) when such determination follows a customer complaint regarding a
shared meter condition or a utility discovery of a shared meter
condition that is not in response to an owner's request for a utility
inspection for a shared meter condition, with respect to utility service
billed after December first, nineteen hundred ninety-six, the utility
shall comply with the provisions of paragraphs (a), (b) and (c) of this
subdivision, and further bill the owner and refund to the shared meter
customer an estimated amount of charges for twelve months of all service
measured by the shared meter; provided, however, that this paragraph
shall not apply to a shared meter condition if service measured through
the shared meter is minimal under commission rules adopted pursuant to
subdivision eight of this section. An owner so billed may petition the
commission or its designee for a determination that the amount of such
bill is excessive and that such bill and refund be adjusted accordingly;
provided, however, neither the adjusted bill nor the adjusted refund
shall be less than twenty-five percent of the total amount of the
original bill. The commission is authorized to make such a determination
and adjustment if it finds that a bill and refund of twelve months'
charges is unduly burdensome and unfair. In making such determination
the commission or its designee shall consider the total amount of the
bill and refund in relation to the shared area charges over such twelve
month period and any other equitable factors established by the
commission; and
(e) the utility shall bill the third party, when third party
involvement exists, instead of the owner, for the applicable estimated
charges for service used by the third party credited by the utility to
the shared meter customer.