(a) If pursuant to the surplus lines provisions of this chapter an insurer has assumed direct risk under a coverage and the premium therefor has been paid to the broker who placed such insurance, the insurer shall be liable to the insured for unearned premiums payable upon cancellation of the insurance, whether or not the broker is indebted to the insurer for such premium or otherwise. This provision shall not affect rights as between the insurer and the broker.
(b) Each such insurer shall be deemed to have subjected itself to this section by acceptance of such direct risk.