I feel for you!!!
We had a contractor do some work, lucky for us he lives across the street and is now a good friend. Shortly after he finished the big job he retired and his son took over. When it was time to do the deck his son was here, dug a hole for the deck footing and DRILLED right through our septic tank!! To make matters worse, he picked up his stuff and LEFT. Never said a word to my husband who was home at the time. Husband went looking for him, found the hole, saw the inside of the septic and damn near blew a gasket himself.
It was very difficult having "words" with Chris (the son) because we were such good friends with Ed (the dad). But Dad and son came over and husband gave son what for and dad backed up husband 100% and told son "if you expect to get more contract work in this town you better make him happy because I'll make sure that he tells everyone what you did".
I say by all means the contractor needs to know what is expected, and when you are not happy, and what he can do to make you happy. I can understand mistakes whether theirs or someone elses, mistakes happen, but regardless of the cause the contractor has to make sure that the mistakes are fixed.