Pre-ordering wasn't a requirement for the 'refund support' from Paradox, I do believe some people have posted in this thread that they got refunds despite buying at a later date. That message is not anything more than a near automatic response. It is clear that they have not actually read what you have written. I'm afraid that if it isn't automatic, that Steam has simply opted to no longer care what Paradox has said. Obviously managing refunds on behalf of others for months on end isn't something they are bound to be glad to do, and might not care to do it anymore.
I suggest you try again, then inform them about the past correspondance and when you asked for the refund here to give a proper timeline etc. The message you sent them can be misunderstood to mean that you just recently asked for a refund, rather than when it was actually viable.
Its my second "automatic response" in a row, both times I've mentioned that I've been talking to paradox, but both times steam has simply ignored it and given me form emails as a response. one time citing only refund for preorders, one time, the courtesy refund (which has been expended for me, on Front Mission Evolved, another preorder I got burned on though not nearly as badly as SOTS2)
I know I could probably keep pestering them about it until either they give me $40 or they temporarily suspend me from the support ticket system, but I'm done I think.
A little over a month between two support ticket systems, the forums, and four support agents with no progress... I dunno, I think at this point its not worth more then $40 to me. In the future I'll just buy post launch, lesson learned, and come back to this game in a year.