(a) An apartment listing service shall, upon written request, refund to a customer all moneys paid by him in excess of thirty dollars if he has not, at the expiration of the contract, rented an apartment through a listing furnished by such apartment listing service. Payment of any refund shall be made within fifteen days following the date of receipt of such request or the expiration of the contract, whichever is later.
(b) A customer shall submit a claim against the surety bond submitted to the commissioner by an apartment listing service pursuant to section 42-103c not later than six months after the apartment listing service ceases operation as a registered service.