Call the ADT home office customer toll-free support line at 1-866-865-5006 and ask for a representative for your area in Michigan to call on you.
Fill out the form with your contact information on ADT's website front page and a sales person will call on you.
Go to a website such as 411.com or phonenumber.com and fill in the business info blanks with "security" or "ADT" for the type of business and your zip code for location. This will give you the contact information for the closest home security dealers to your location.