Unless the commission otherwise orders, no change shall be made by any public utility in any rate, fare, toll, rental, charge or classification, or in any rule, regulation or contract relating to or affecting any rate, fare, toll, rental, charge, classification or service, or in any privilege or facility except after thirty (30) days’ notice to the commission and to the public as herein provided. Such notice shall be given by filing with the commission and keeping open for public inspection new schedules stating plainly the change or changes to be made in the schedule or schedules then in force, and the time when the change or changes will go into effect. The commission, for good cause shown, may allow changes without requiring the thirty (30) days’ notice herein provided for, by an order specifying the changes so to be made and the time when they shall take effect, and the manner in which they shall be filed and published. When any change is proposed in any rate, fare, toll, rental, charge or classification, or in any form of contract or agreement or in any rule, regulation or contract relating to or affecting any rate, fare, toll, rental, charge, classification or service, or in any privilege or facility, attention shall be directed to such change on the schedule filed with the commission by some character to be designated by the commission, immediately preceding or following the item.