That is a good start. That is, if you signed an agreement, that agreement is what will determine your rights in this matter. Obtaining and reading a copy would be a good start to sorting this out.
Lets back up...
When parties enter into an agreement for services, both parties are bound by the terms of the agreement.
With certain exceptions, there is no automatic "right to rescind" (right to cancel) the agreement.
Lets start with agreements you CAN cancel
Federal law and MI law give a 3 day right to cancel contracts made in a "door to door" sales (so a person comes to your home and you sign an agreement to purchase a product or service? You have 3 days to cancel that agreement). Federal law also gives 3 days to cancel a mortgage loan.
MI law gives one day to cancel a home improvement contract.
What you are describing, since the agreement was entered into over 3 days ago, you are too late to rescind.
Next, under contract law, you can cancel the agreement and the other party is required to "mitigate damages"...that is, if you give the other side notice that you are cancelling, they are required to take steps to minimize the expenses they suffer.
Let me give an example: say your contract was for installation of a new bathroom. You sign the contract...and a week later you cancel. The contractor can sue you for any damages they can prove. So, for example, if they contractor spent money on materials, they can sue you to recover. OR if they turned down other work (to make room for your job) they can sue for lost income. If they sue, they have to prove how they were harmed.
And this is where the contract comes into play...
It is VERY common for agreements like you describe to have a "liquidated damages" provision where the contract states how much you owe if you cancel. You will want to review this....since if the case lands in court, they can hold you to the agreement you signed.
This is the part of my job I don't like...when the law is not in favor of my customer. I wish I could tell you that you can rescind this contract without recourse from the company, but I can only provide you information based on the law so that you can act on the best available information to you...I wish I had better news, but can only hope you recognize and understand my predicament and don't shoot the messenger. I'm sorry!
Please let me know if you have more questions. I am happy to help if I can. Otherwise, please rate the answer so I may get credit for my work.