In counties with 3,000,000 or more inhabitants, at its meeting for the purpose of revising and correcting the assessments, the board of appeals (until the first Monday in December 1998 and the board of review beginning the first Monday in December 1998 and thereafter), upon complaint filed by a taxpayer or taxing district as prescribed in this Code, may revise the entire assessment of any taxpayer, or any part thereof, and correct the same as shall appear to the board to be just. The assessment of the property of any taxpayer shall not be increased unless that taxpayer or his agent shall first have been notified in writing and been given an opportunity to be heard.
35 ILCS 200/16-120