/caveat/ I do not know these guys and rely only on the information you provided /end of caveat/
This is really not a way to treat an unhappy customer. Even if your comments on their sales process were a little graphic (this is the internet), they were fact based and you did praise them on other aspects. Very unprofessional for them to get upset about it. On the contrary, they should go out of their way to figure out why you were unhappy and diagnose their operations.
You can learn a little from happy customers, but you rarely get an occasion to learn from unhappy customers (they just don't come back and you never know about the issue).
In addition, if you can flip someone active in a forum by going out of your way (which may be very small things for them), you can get great viral advocacy.
IMHO, their behavior (as you described it) is similar to that of my 4 year old son.
When I tell him that "no, I will not go out to buy you a professional fishing rod right now (at 8pm)". Just gets angry, shouts and goes to his room.
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