Cal. Civ. Code § 1812.122

Any transfer by a discount buying organization of its duty or obligation to provide services to buyers under its contracts for discount buying services to another individual, corporation, or other business entity, as a result of which a buyer shall have available substantially fewer goods and services, shall constitute a complete defense to an action for further enforcement of or collection on such a contract for discount buying services which may be asserted by any buyer who did not consent in writing, after a full and fair disclosure of the categories of goods and services to be provided by the new discount buying organization, to such transfer of the duty or obligation of performance, and shall entitle such a nonconsenting individual to rescind the contract and obtain a pro rata refund from the transferor.