If a customer reports trouble on a line, a LEC shall, without charge to the customer and by use of whatever means necessary, determine whether the trouble is on the LEC or customer side of the network interface. For a LEC subject to an alternative form of regulation plan on January 1, 2006, this section shall not be effective until the expiration of its alternative form of regulation plan.
N.M. Admin. Code § 17.11.16.31