(d) When a defendant in a non-IV-D case, as defined in G.S. 110-129, fails to make required payments of child support and is in arrears, upon notification by the State Child Support Collection and Disbursement Unit the clerk of superior court may mail by regular mail to the last known address of the defendant a notice of delinquency that sets out the amount of child support currently due and that demands immediate payment of the amount. Failure to receive the delinquency notice is not a defense in any probation violation hearing or other proceeding thereafter. If the arrearage is not paid in full within 21 days after the mailing of the delinquency notice, or is not paid within 30 days after the defendant becomes delinquent if the clerk has elected not to send a delinquency notice, the clerk shall certify the amount due to the district attorney and probation officer, who shall initiate proceedings for revocation of probation pursuant to Article 82 of Chapter 15A or make a motion in the criminal case for income withholding pursuant to G.S. 110-136.5 or both. When a defendant in a IV-D case, as defined in G.S. 110-129, fails to make required payments of child support and is in arrears, at the request of the IV-D obligee the clerk shall certify the amount due to the district attorney and probation officer, who shall initiate proceedings for revocation of probation pursuant to Article 82 of Chapter 15A or make a motion in the criminal case for income withholding pursuant to G.S. 110-136.5 or both.