Notwithstanding another law to the contrary, the department of human services serves as the state disbursement unit. The department must establish, advertise, and maintain a customer service unit for the express purpose of receiving and responding to citizen inquiries and complaints concerning child support collections and disbursements. Notwithstanding another law to the contrary, if the department retains a contractor to fulfill the department's obligations under this section, then the contractor must establish, advertise, and maintain a customer service unit for the express purpose of receiving and responding to citizen inquiries and complaints concerning child support collections and disbursements.