Notwithstanding any provision of an individual or group policy or contract of health and accident insurance, delivered within the state, whenever such policy or contract shall provide for reimbursement for any service within the lawful scope of practice of a duly licensed specialist social worker authorized to engage in private, independent practice under subsection (a) of Kan. Stat. Ann. § 75-5353, and amendments thereto, within the state of Kansas, the insured, or any other person covered by the policy or contract shall be allowed and entitled to reimbursement for such service, unless subject coverage in those insurance plans in existence on or before March 15, 1989, is refused in writing by the policyholder prior to March 15, 1989, irrespective of whether it was provided or performed by a duly licensed physician or a duly licensed specialist social worker authorized to engage in private, independent practice under subsection (a) of Kan. Stat. Ann. § 75-5353, and amendments thereto.