Cal. INS § 11624.4

Every insurer to whom an assignment is made shall do all of the following: (a) Provide policyholders with information on how to report claims. (b) Provide brokers and agents with a toll-free telephone number or accept their collect calls for the purpose of providing agents and brokers with a means of communicating with the insurer in order to rectify errors in applications or endorsements for assigned-risk coverage. (c) Reply in writing within 15 days to complaints disputing the amount of premium charged for coverage under this article.