It shall be unlawful for a hauler of milk, cream or other dairy products or any other person or agent, receiving such products by weight or butterfat content, fraudulently to manipulate the weight of milk, cream or other dairy products of any patron, to take an unfair sample thereof or fraudulently to manipulate such samples in any manner. In case weighing and sampling is done by a hauler, he shall hold a license for a weighman and sampler as set out in § 39-33-1260.