Cal. Business and Professions Code § 17500.5

(a) It is unlawful for any person, firm, corporation or association to falsely represent by advertisement the quantity of any article so advertised that will be sold to any one customer on his demand in a single transaction, and willfully or negligently to fail to include in such advertisement a statement that any restriction that is in fact put upon the quantity of any article so advertised that is sold or offered for sale to any one customer on his demand in a single transaction. (b) Any person, firm, corporation, or association who, by means of such false or negligent advertisement or publicity, induces any individual retail purchaser and consumer to enter any place of business designated therein seeking to buy any article so advertised or publicized, and then refuses to sell to such person the article at the price advertised in any quantity then available for sale on said premises, shall be liable to each person so induced and refused, for the losses and expenses thereby incurred, and the sum of fifty dollars ($50) in addition thereto. (c) Nothing in this section shall affect any right a seller may have to refuse to extend credit to a customer, and this section shall not be applicable to a customer purchasing for resale. (d) The provisions of subdivision (b) are applicable only to actions brought in the name of, and on behalf of, a single plaintiff and shall not be applicable in multiple plaintiff or class actions.