A customer desiring the size or location of a service pipe or meter changed will make written application and after inspection has been made and the application has been approved, the City Superintendent will provide an estimate of the cost of all labor, materials, and hookup fees connected with such proposed change, and thereafter upon receiving payment of estimated cost, the change will be made by the City. If the change includes an increase in the hookup size, the customer shall pay the difference between the previous hookup size and the new hookup size according to the current hookup fee schedule set forth in Section 13.04.240 of this code. After completion thereof, the actual cost of the change shall be computed and the difference from the estimated cost, if more, shall be paid by the consumer to the City. If less, paid by the City to the consumer.