Ownership by the applicant or licensee or by a shareholder, partner or beneficiary thereof of a substantial or controlling interest in the business of a retail seller from which it purchases any retail contracts, retail charge agreements or evidences of indebtedness unless the retail contracts, retail charge agreements or evidences of indebtedness used in the retail installment transaction provide expressly and prominently that all defenses of the retail buyer may be asserted equally against the sales finance agency and the retail seller involved in the transaction.