(4) Where a meter through no fault of the consumer fails to record within the margin of error allowed by subsection (2), the consumption of electricity by a consumer, the Company must, upon the written request of the consumer, examine the accounts of such consumer and from such examination compute the average monthly sum charged to that consumer over the 6 months immediately preceding the meter failure, or from the date of connection, whichever period is the shorter, and the Company may charge or credit as the case may be, the account of such consumer at a rate not exceeding such average monthly charge.