I think everyone on this thread agrees that this is atrocious customer service, and that the president of a company should not speak to a customer that way even if they've got it coming.
The reason that is getting downplayed is that bad customer service here is the less striking issue. What jumps out more is the total lack of self awareness or personal responsibility. Instead of thinking that gee, my really rude email got a really rude response, the OP is boggling that her total lack of class and communication skills was with the same. We like to expect that an executive will rise above that tone, but no one acquainted with the real world could really manage to be baffled that nasty email got nasty reply.
I think this obvious reciprocity of bad behavior is what the karma comments are in reference to. The OP handled a situation with childish, impulsive bad manners...and in response, the president of the company handled the situation with childish, impulsive bad manners.