If either party to the transaction of purchase and sale of milk between a milk producer or a milk seller and a licensed buyer of milk shall be dissatisfied relative to the transaction, he may apply to the secretary in writing, within sixty days after the delivery of the milk to the licensed buyer, for an investigation.
The secretary shall treat such application as a complaint and shall cause a full investigation of the transaction complained of to be made either by himself or one of his assistants, in the manner provided in sections 4:12-14 and 4:12-15 of this title.