Unless the department otherwise orders, no household goods warehouse operator may change any rate except after ten days’ notice to the department and to the public pursuant to this section. Notice must be given by filing with the department and keeping open for public inspection new schedules or supplements stating plainly the changes to be made in the schedules then in force and the time when the changes will go into effect. The department for good cause shown, may, after hearing, allow changes without requiring the ten days’ notice by an order specifying the changes to be made, the time when they shall take effect, and the manner in which they shall be filed and published.