Nevertheless, please don't post comments like yours on Hacker News either, no matter how wrong the other person may be. In such extreme cases, here's what we ask.
Definitely do: flag the comment by clicking on 'link', which takes you to the item page for the comment, and then clicking on 'flag'. We monitor those flags and take action based on them.
Maybe do: send us an email to make sure we take a close look.
Definitely don't: lash back. All it does is degrade the discourse further.