Section 100.12 - Refusal of commission merchant to furnish written statement of transaction prima facie evidence of gambling(1) Every person doing business as a commission merchant or broker shall furnish, upon demand, to any person for whom he or she has executed an order for the purchase or sale of a commodity, whether for immediate or future delivery, a written statement containing the following information:(a) The name of the party from whom the commodity was bought or to whom it was sold, whichever the case may be; and(b) The time when, the place where, and the price at which such commodity was bought or sold.(2) Refusal upon demand to furnish the written statement specified in sub. (1) is prima facie evidence that the purchase or sale of the commodity was not a bona fide business transaction.(3) Transactions by or between members of a lawfully constituted chamber of commerce or board of trade which has been organized pursuant to the laws of this state are prima facie valid if they are conducted in accordance with the charter of such chamber of commerce or board of trade and the rules, bylaws and regulations adopted thereunder.