Ill. Admin. Code tit. 83, § 410.45
a) Each entity shall maintain a customer call center where customers can reach a representative and receive current information. At least once every 6 months, each entity shall provide written information to customers explaining how to contact the call center. The average answer time for calls placed to the call center shall not exceed 60 seconds where a representative or automated system is ready to render assistance and/or accept information to process calls. The abandon rate for calls placed to the call center shall not exceed 10%. Each entity shall maintain records of the call center's telephone answer time performance and abandon call rate. These records shall be kept for a minimum of 2 years and shall be made available to Commission personnel upon request. In the event that answer times and/or abandon rates exceed the limits established above, the reporting entity may provide the Commission or its personnel with explanatory details. At a minimum, these records shall contain the following information in monthly increments: