Is it legal to change an affidavit after it is signed?

I am going through a permit process in a city in Illinois. Part of the process requires that I complete a affidavit of disclosure of property interest. I did prepare this, signed it, had it notarized and gave it to the city as part of my permit submittal. I got the permit back, but the affidavit has been changed without my knowledge or authority. Is this legal? If not who should I notify this occurred and what are the penalties?