e)- change friends.
You tried to do the man right by offering 2 other nucs and he's still not happy. At a minimum he should have thanked you to acknowledge your efforts to right a so called wrong. Sounds like you should have offered him 200 pounds of honey, you know for the loss of honey from the "crap" you sold him He sounds like the kind of person who is not very easily satisfied and easily dissatisfied. I know it's kinda hard not to take it at heart but try not to take it personally. I know that I would not sell any more nucs to that individual. Criticism can be good but the kind that was given to you, most people I know can go without.