That's unfortunate. I'd try sending another request via http://www.thewitcher.com/backup/ providing all the info they demand for digital copies of The Witcher (CD keys from the retail version can be redeemed right away). My guess is that they've heavy workload with the upcoming Witcher 3 right now, but eventually that's no excuse for ignoring you completely.
You can also try to contact GOG support. They're very helpful, though they might not be allowed to confirm digital copies, but have to rely on CD Projekt Red's decisions.

Interesting...the standard message is to wait 72 hours. I did that, but still hadn't heard, and did the same things you did and like you I got no response...;) Then I sent an email to normal tech-support, where I very courteously and politely stated the problem, and 3-4 days later the game was added to my Gog collection. I'm with the other posters and imagine they have a terrific backlog of regular work and that this is something they do when they can spare the time. A courteous note to regular tech support can't hurt.

Also, make sure that your email includes the necessary information, like your code # and a copy of your .jpg, etc. That is what I did--it's bound to expedite matters. My original copy of Witcher 1 was the 1.4 version on a multiple-CD-ROM set of disks, and I still had the original manual. I took a .jpeg of my manual open to the page with my original key (which was not accepted by the automatic W1 backup generator), and I wrote my code # assigned by the Gog backup program on that page in very big letters. I surrounded the open manual page with my disks which clearly showed the title of the game. The .jpeg showed all of that clearly. The whole process took 7-10 days--can't recall exactly.

Per Witcher 2, which I bought from Steam, that was much easier. My Steam copy had a number in the registry which Gog accepted immediately. They sent a purchase key for W2, IIRC, via email.