Cal. Pub. Util. Code § 708.3

Whenever a business transaction of an electrical, gas, water corporation with 10,000 or more service connections, or telephone corporation is such that a personal appearance by a person is required by the corporation and the person is unable to appear at the corporation’s place of business during the corporation’s usual business hours, then the corporation shall provide a reasonable and convenient alternative to the person such as an appointment outside the corporation’s usual business hours or allowing the person to conduct the transaction by telephone, or mail, or both.