Listing of offices at City Hall, with phone numbers and contact information. http://www.cityofmacomb.com/departments.html
Application for water/sewer service (for tenants). https://www.cityofmacomb.com/App_renter.html
If you have a problem with loud/unruly persons or illegal/unsafe behaviors, and you haven't had any luck asking the people to stop the behavior, call the Macomb Police at 309/833-4505. They do NOT tell the people where the complaint is issued from, but without a complaint, they CANNOT respond.
If you have a problem with your landlord or a property violating an ordinance/law, submit all correspondance to that person(s) IN WRITING, keeping a copy. It is a good idea to send it via registered/certified mail. To send a complaint about a property to the city, you can call 309/833-4944, or submit your complaint via the city of Macomb's Form.
[Online Complaint Form]