Except as provided in subsections 2 to 5 of section 392.200, proposed changes in rates or charges, or any classification or tariff provision affecting rates or charges, for any competitive telecommunications service, shall be treated pursuant to this section as follows:

(1) Any proposed decrease in rates or charges, or proposed change in any classification or tariff resulting in a decrease in rates or charges, for any competitive telecommunications service shall be permitted only upon the filing of the proposed rate, charge, classification or tariff after one day’s notice to the commission; and

(2) Any proposed increase in rates or charges, or proposed change in any classification or tariff resulting in an increase in rates or charges, for any competitive telecommunications service shall be permitted ten days after the filing of the proposed rate, charge, classification or tariff and upon notice to all potentially affected customers through a notice in each such customer’s bill at least ten days prior to the date for implementation of such increase or change, or, where such customers are not billed, by an equivalent means of prior notice.