I assume it was just a form letter, and I have difficulty getting angry at / being insulted by form letters. It's an efficiency thing that probably adequately covers more inquiries than you would think. (Government is a different story; I get annoyed by government form letters because they're supposed to represent me, and if they can't be bothered with even pretending to listen, then it pisses me off.)

That's not to say I don't get frustrated at them, however. A few weeks ago, I was looking to buy Petzold's Code from Amazon.ca, and noticed that one of their pages, linked from the checkout page, listed the free shipping option for orders over $39. They had changed it to $25 probably more than a year ago at this point, presumably partially because that's the threshold for Amazon.com and partially because that's the free shipping price the otherwise more expensive Chapters.ca uses. I sent them a message telling them the listed threshold was wrong, with a screenshot, and explaining that I did know the real price by quoting it. They responded with a form letter telling me what the threshold was without any indication that anyone had noticed that I'd pointed out a problem with their site.

I sent a second message explaining that I'd got a form letter and this time they responded that the issue had been forwarded to the relevant department.

I just checked, and the incorrect value is still shown on the website. C'est la vie.