It seems to be the normal process to require a second email to get your first one looked at, this seems to be the norm on more airlines than just CO. I guess they figure they can insult our intelligence on the first reply and hope we just go away.
ACtually, I doubt an agent even looks at it. They probably have a keyword check program that auto-replies based on keywords in your letter. If you send a reply to that, it knows that you were unhappy with the response and a human will look at it. That eliminates a lot of questions. I suspect that is SOP.
There's a reason people love Nordstrom... they treat customers well. I was with my then-BF at Macy's in SF, and nobody there was around to help us pick out a suit. After milling around and looking for a while, I asked an employee directions to Nordstrom, suddenly two of them were being VERY helpful and offering additional discounts.