If the secretary determines that the fund is liable for any nonpayments to producers, the secretary shall provide to the producers, who have a contract with the defaulting handler on file with the secretary, a claim form. The claim form, which shall be verified, shall be returned to the secretary within 60 days from the date the claim forms are mailed by the secretary. The producer need only verify that a nonpayment has occurred. The amount of the nonpayment shall be determined by the secretary.