IL landlord tenant laws

Tenant/Landlord: Received letter from law firm old landlord back rent $1245. Responded with letter describing conditions in building (eg panes of glass in window so thin and loose one fell out of my second floor window to sidewalk below, space heater not working for week without reduction in rent, repairs done on building after which loose insulation lett on stairs for a few weeks etc) in hopes of reduced amount owed. Never heard back but was served with papers for a court date, the amount now $1645 + court costs. Called law firm to make payment arrangements. Letter arrived to day with Agreed Order to sign and return $655 due Jan 28, $600 due Feb 28 and then by 28th of each month thereafter. The total amount due is not spelled out, they did not offer me any other options than three payments which poses a hardship, I feel that in signing I could be paying forever. Let me know what I should do. Thanks - Is this your question? Add additional information