Section 180 - Rates and charges; contract carriers1. No contract carrier of property by motor vehicle shall engage in such transportation unless a copy of the contract and copies of any amendments to that contract are filed with the commissioner in accordance with any rules and regulations that the commissioner may prescribe.2. No contract carrier of property by motor vehicle shall charge, demand, collect or receive a different compensation for transportation or for any service in connection therewith than the rates and charges specified in the contract in effect and on file with the commissioner at the time of shipment and no such carrier shall refund or remit in any manner or by any device, directly or indirectly, or through any agent or broker or otherwise, any portion of the rates or charges so specified, nor extend to any person any privilege for transportation except as is specified in its contract.3. Initial, first time, contracts shall be published and filed with at least one day's notice to the commissioner and must be in accordance with the rules and regulations that may be prescribed by the commissioner.4. No reduction shall be made in any rate, charge, or classification, or the value of the service thereunder in any contract except after at least thirty days' notice of the proposed change filed and posted in accordance with the rules and regulations that may be prescribed by the commissioner. The commissioner may for good cause shown, allow changes on less than thirty days notice or modify the requirements of this section either in particular instances or by general order applicable to special or particular circumstances or conditions.5. Whenever, after a hearing, upon complaint or on the commissioner's own initiative, the commissioner finds that any charge of any contract carrier or contract carriers is unreasonably low or any rule, regulation or practice of any such carrier or carriers affecting such charge, or the value of the service thereunder results in an unreasonably low charge, the commissioner may prescribe such charge or such rule, regulation or practice as the commissioner determines may be necessary or desirable in the public interest. All complaints filed under this subdivision shall state fully the facts complained of and the reason for such complaint and shall be made under oath.6. Whenever there shall be filed with the commissioner by any such contract carrier any contract or amendment to a contract stating a reduced charge, or which has the effect of reducing a charge by means of any rule, regulation or practice, the commissioner may, upon complaint or on the commissioner's own initiative, suspend and defer the implementation in part or in whole of any such contract or contract amendment for a period of six months. After investigation and hearing, the commissioner may allow the suspended matter as proposed or issue an order directing the carrier to cancel or modify the proposed contract or contract amendment. Provided, however, that if a decision is not rendered within the six month suspension period the proposed contract or amendment shall go into effect at the end of such suspension period. In any hearing to determine the reasonableness or lawfulness of a proposed reduction the burden of proof shall be on the carrier or carriers proposing the reduction.