I had a sales rep come to give me an estimate for 2 replacement windows, new gutters, and new vinyl siding. He gave me the quote and I accepted his offer. We signed a contract and I gave him a check for the full amount. Several hours later he called me to say that his numbers were off by about $8000. He wants to come over right away and have me cancel the agreement. I told him to call me tomorrow. Do I have a right to hold him to this contract?
It would appear that you have not only created a contract (offer and acceptance), you have completed your part of the bargain (PAYMENT IN FULL).
But, to be on the safe side, I'd discuss this with a local attorney and have him or her read and interpret the document you are calling a contract.
Barring that, in your state, you have LARA.
Its your state's agency that regulates and licenses contractors.
You could run this by LARA (website below), and see what Michigan state law says.
http://www.michigan.gov/lara/0,4601,7-154-35299_61343_35414_60647_35455---,00.html
https://www.michigan.gov/statelicensesearch
But, the right thing to do often isn't the legal thing to do.
The salesman is a poor working stiff.
What's the delta here?
Is it $200, or $10,000?
In the end, it might be easier to invite the sales guy and his manager (business owner) to meet with you.
You can discuss the situation, and ask them what are they willing to do, if you work with them?
I bet if you contact Brian Elias, he'll work it out and everyone will be happy.
http://www.hansons.com/Hansons_Story.htm