Not to pile on, but I too have had very good luck writing polite letters and getting things fixed even outside of warranty. I always copy three people:
1. The CEO
2. Customer Service
3. Sales (sales people understand better than anyone else the importance of keeping customers happy so they become REPEAT customers)
I have done this with a Mossberg rifle that would not accept new magazines but which I had bought gently used and was outside of warranty. Because the mag that came with it fit fine, but new ones would not, I thought the mags were at fault. They fixed my rifle AND gave me five new mags. I love Mossberg!
I did it with a Linksys router that didn't work out of the box, but had been sitting on my shelf for a couple of years. They sent me a brand new unit. I used to love Linksys, but now they're owned by Cisco, and I don't like some things that Cisco is doing.
I did it with a Bosch circular saw whose motor commutator literally exploded while I was trimming a new solid core door to put on my then baby son's room--again, outside of warranty. They rebuilt the motor and I still have that saw. And they lived up to their reputation for great tools and appliances.
Most recently I did it with Smith & Wesson when I never received the box of 22LR ammo they promised as a promo with purchase of a new M&P15-22. Calls and emails to customer service were getting me only canned responses that the shipment was being processed by a handing firm. I got not one but TWO boxes of the ammo.
I do have one question--have you already paid this contractor for the work they have not yet done? Never pay a contractor in full until the work is done to your satisfaction. Once they have your money, you have no leverage over them.
"Darth Vader was a sap"