In the event the Industry Placement Facility accepts premium payments from licensed premium financing companies and whenever a financed FAIR Plan insurance contract is cancelled in accordance with § 521 of the Illinois Insurance Code, the insurer or Industry Placement Facility shall return whatever gross unearned premium is due under the insurance contract to the premium finance company effecting the cancellation for the account of the insured or insureds less the proportionate amount of the commissions paid by it to the producers of such FAIR Plan risk, prorated as to the unearned portion of the premium, which amount such producers shall return to the premium finance company. In the event of cancellation as set forth above the Industry Placement Facility may deduct and retain from the return premium a reasonable amount as a service charge.