Cal. Fam. Code § 17800
Each local child support agency shall maintain a complaint resolution process. The department shall specify by regulation, no later than July 1, 2001, uniform forms and procedures that each local child support agency shall use in resolving all complaints received from custodial and noncustodial parents. A complaint shall be made within 90 days after the custodial or noncustodial parent affected knew or should have known of the child support action complained of. The local child support agency shall provide a written resolution of the complaint within 30 days of the receipt of the complaint. The director of the local child support agency may extend the period for resolution of the complaint an additional 30 days in accordance with the regulations adopted pursuant to Section 17804.
Ca. Fam. Code § 17800