If a claim for lien has been filed pursuant to the provisions of sections 429.600 to 429.627 with the county recorder of deeds and such claim has been paid in full or if the lienor fails to institute a suit to enforce the lien within the time as provided by law, the real estate broker shall acknowledge satisfaction or release of such lien in writing upon written demand of the owner within thirty days after such demand.
§ 429.623, RSMo