(b) If the customer pays an advance fee, the contract with the apartment information vendor shall contain a provision stating that the customer may, under the circumstances set forth in this paragraph, recover his advance fee less the amount deducted for administrative services. The vendor shall be entitled to his fee when a customer has leased or rented a private dwelling, abode or place of residence through the information provided by the vendor. Within ten days of the receipt by the apartment information vendor of written notice stating that the customer paying an advance fee has not leased or rented a private dwelling, abode or place of residence through the information supplied by the vendor and does not intend to rent any such private dwelling, abode or place of residence, the vendor shall refund the advance fee, less the fee for administrative services, to such customer. The vendor shall also be required to refund any portion of the advance fee in excess of one month's rent to a customer who has leased or rented a private dwelling, abode or place of residence through the information supplied by the vendor.

(c) Notwithstanding anything in this subdivision five to the contrary, if the services to be rendered by the apartment information vendor to a particular customer relate exclusively to acting as an apartment sharing agent, the vendor may retain the full advance fee, whether or not the customer leases or rents a private dwelling, abode or place of residence through the information provided by the vendor, and the provisions of paragraphs (a) and (b) of this subdivision five shall not be applicable to such transaction.