Any domestic subscriber may appeal an adverse decision of the utility employee to a management office designated by the utility or to the utility board when designated by the utility. Each utility shall establish a hearing procedure to resolve utility bills appealed by domestic subscribers. The procedure shall be in writing and a copy of such procedure shall be furnished upon the request of any domestic subscriber. Such appeal shall be filed with the management office or utility board within the time specified in the procedures established by the utility. Nothing in sections 70-1602 to 70-1615 shall prohibit any utility from providing such additional stages of appeal as it may deem appropriate.