220 ILCS 5/10-109

The Commission shall have power to receive complaints regarding loss or damage occasioned by a public utility, and to make inquiry as to the methods of adjusting such claims. All claims against any public utility for loss of, or damage to property, or for any other loss or damage, in connection with a public utility service, not covered by the preceding paragraphs of this section, if not acted upon within 90 days from the date of the filing of the claim with the public utility, may be investigated by the Commission, in its discretion, and the results of such investigation shall be embodied in a special report which shall be open to public inspection.