M & M PAINTING

I contracted with M and M Painting in August to paint my home in four colors with Sherwin-Williams Duration paint. At that time, there was a red flag that I should have recognized: the contractor asked for $7,000 of the $12,000 job as a down payment. As a percentage of the estimate, that's more than I have ever been asked by a contractor, but I provided it without protest.
The work progressed well, however, and I had high hopes. The painters seemed to do a very good job preparing the surface, and the paint was applied with great care. Then the M and M owner Mark Maijala approached me and said there were serious repairs that needed to be done to my small enclosed front porch and entryway due to rotting wood and problems with ventilation. The cost to fix those,  to rebuild a small enclosure for the back porch, and do other minor carpentry work would be an additional $8,000, he said, with $5,000 down, which I gave him. It seemed high to me, but I felt like I had no other choice if I wanted to have my home repaired and painted properly.
Meanwhile.... the painting contract stipulated that Sherwin-Williams Duration paint would be used, yet there were no cans at the job site with any brand names on them. I went to the local Sherwin-Williams dealer, who informed me that he had not sold any Sherwin-Williams paint to Mr. Maijala since we had signed the agreement.
At that point, I phoned Mark Maijala and said that if he could not produce receipts for the Duration paint, I would cancel the contract. He came to my home later that day and said that he had used Glidden paint to save money because it had taken longer to prep the house than he thought. Rather than tell me this and adjust the price upward, he switched to a cheaper paint. He said he did this because some clients refuse to adjust the contract when labor costs go up.
He did this even though I had told him at the beginning of the job that I knew old houses were full of surprises, and that I wanted him to let me know if additional work needed to be done.
It also seems inconsistent with the fact that he very willingly came to me for an $8,000 change order when his crew discovered that extra work needed to be done on my porch.
I have told Mr. Maijala that I will pay him for materials and for labor up until I ended the contract, plus a 15 percent profit. I expect to see receipts and payroll records to verify those numbers. He said he would contact me the week ending Saturday, Sept. 29, with that information, but he did not.