New York Laws
Article 6 - Provisions Affecting Two or More Kinds of the Public Service and the Persons and Corporations Furnishing Such Service
118 - Payment to an Authorized Payment Agency.

(b) If a residential customer becomes eligible for a lower rate
because he or she changes the character of the service received and if
excess payment resulted from the failure of the customer to notify the
utility or municipality providing service of a change in the character
of service received or from the failure of the utility or municipality
to change the rate after such notification by the customer, such a
customer will be entitled to such lower rate from the date the change
occurs but such a customer shall not be entitled to such lower rate for
more than twenty-four months prior to the giving of actual notice to the
utility or municipality providing service.