Ill. Admin. Code tit. 83, § 460.320
a) Each MSP shall maintain a customer call center where customers can reach a representative to discuss meter service issues. At least once every six months, each MSP 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 MSP 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 two 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 MSP may provide the Commission or its personnel with explanatory details. At a minimum, these records shall contain the following information in monthly increments: