When did you send in your e-mail? GOG is a small shop that usually takes 24-48 hours to respond to requests. However, they don't usually work weekends (especially this past weekend), so if, for example, you sent in a support request on Friday afternoon, you might not get any responses until the following Tuesday. Additionally, the forums are really intended for community support, so if you haven't got any answers to a forum post yet, blame the community, not GOG.
As for why this thread got a response, if you notice, it is marked as a comment, meaning it appears on the game's review pages in the store for anyone and everyone to see. It contains completely false information that needed to be corrected.
That's fair enough, but it still took a whole week to reply to my emails and that may have just been down to complaining on the forums so I would like them to speed up the customer service. Also this isn't an isolated case for me, as I've previously emailed the support in May of last year and it took 9 days for a reply.
At the end of the day, if you buy something in a shop and it doesn't work, you can speak to someone about it straight away and get your money back if necessary.