I'm sorry to hear you've had some trouble on this project. Certainly, taking a down payment and failing to ever proceed with work is against the law. Once payment is made pursuant to the contract, the work should be undertaken as set out in the agreement. If it isn't, a contractor could certainly face liability. However, without knowing more information about the circumstances or the agreement at hand, it's hard to provide additional insight here.
If a contractor has taken a down payment and has never shown up to provide the work that was contracted, demanding that the contractor either perform as contracted or that they return the deposit is likely a good start. Further, if talking it out isn't fruitful, demanding the return of payment through a more official demand letter, potentially written by an attorney, may help recover payment. Finally, making an official claim for payment in small claims court and making a complaint to Michigan's Licensing and Regulatory Affairs department might be helpful. If the contractor is licensed, making a claim against their license bond could do the trick, too.