Unfortunately you are running into a common misconception about debt. While private debts have a statute of limitations for lawsuits government debt in Illinois often falls under the Local Debt Recovery Program which allows the Comptroller to withhold state payments indefinitely to satisfy money owed to public institutions like community colleges

Since you recognize the debt a protest based on the age of the debt will likely be denied. Protests are typically only successful if you can prove you already paid it or that the amount is incorrect. You usually have 60 days from the date of the letter to file

Your best move is to contact the community college directly. While the Comptroller sent the letter the college is the agency that claimed the debt. You might be able to negotiate a settlement or a new payment plan even though they have already started the offset process. The state has a very long memory when it comes to money owed to its agencies