To collect the payment due, the custodian of a child, or the agency on behalf of that person, shall file with the court (1) a motion requesting establishment of a judgment; (2) an affidavit that states that one or more payments of support are 30 or more days past due and that specifies the amounts past due and the dates they became past due; and (3) notice of the obligor's right to respond. Service on the obligor must be in the manner provided in AS 25.27.265. The child's custodian, or the agency on behalf of the custodian, shall file with the court proof of service of the petition, affidavit, and notice. The obligor shall respond no later than 15 days after service by filing an affidavit with the court. If the obligor's affidavit states that the obligor has paid any of the amounts claimed to be delinquent, describes in detail the method of payment or offers any other defense to the petition, then the obligor is entitled to a hearing. After the hearing, if any, the court shall enter a judgment for the amount of money owed. If the obligor does not file an affidavit under this section, the court shall enter a default judgment against the obligor.