If you hire someone to do some work around your house and they don't do it right, do you call them up and tell them about it and try to get them to come back and fix it, or do you just resolve never to hire them to do anything else for you? Assume the work left undone is the equivalent of $100 or less.
IN THE COMMENTS: Some excellent advice from people who know how this problem looks to the contractor who did the work.
UPDATE: Spurred on by help from the commenters, the timid householder did call the contractors and had a a completely pleasant conversation in which her view of what still needed to be done was never questioned. The needed work will be done next week.