Section 16-11-35 - Adjustment of bills for meter error(a) Whenever the test of a meter reveals it to be fast by more than four per cent, the gas company shall refund to the customer such percentage of the amount of bills covering the consumption indicated by the meter for the previous six months as the meter was found to be in error at the time of test, unless it can be shown from the records of either party that the error found has existed for a greater or lesser period, in which case the refund shall cover such actual period.(b) In the case of a nonregister meter, the customer may be billed on an estimate based on previous bills for similar usage.(c) If unmetered gas is used without permission, the customer may be billed on a reasonable estimate of the gas consumed.Conn. Agencies Regs. § 16-11-35