This number is one of many that belongs to Kensington Research and Recovery at 1 East Wacker Drive, Ste 2350, in Chicago. It doesn't matter if you are on the Do Not Call Registry, as that is not enforced. If you are on a DNCR, you can pursue a suit on your own, but it might not be worth the money. Do a search via a search engine if you want to learn more. They will state that the assessment of your property is too high, and that they can save you money by appealing it. If they call you , then it probably is too high, but you can appeal it on your own at the Assessor's Office and the Cook County Board of Review.