US WEST Communications' Utah customers who had inside wiring maintenance contracts between March 1, 1982, and Dec. 31, 1989, will be eligible for a refund following rulings by federal judges in New Mexico and Colorado.

The ruling affects customers in Utah, Arizona, Colorado, New Mexico, Idaho, Montana and Wyoming.The judges approved a stipulated settlement Monday between US WEST and groups that filed class action suits against the company that contended the company imposed a billing surcharge for the service on many customers without their consent during the specified time period. Under the settlement, residential and single-line business customers who did not make use of the agreement during the affected period will be eligible to receive a 65 percent refund of the service fee.

The total cost to the company will be about $100 million. Customers affected are those who were charged for Basic Wire Maintenance, LineBacker Plus and UniSTAR Tier 1.

In January 1990, all US WEST customers were notified that the service was optional and given an opportunity to withdraw.

US WEST and the groups who filed the suit are now working on a claim form that will be sent to all customers eligible for the refund. The company expects to make the refunds over a six-month period once those eligible have been identified.

Anyone who used the service during the specified time period or who filed a form asking to be exempted from the class action suit will not be eligible.