Ok then.. but that's still effin' scary O_o'

those things come from different servers, I believe. GOG uses a CDN provider to deliver their downloads, Edgecast, if i'm not mistaken.
A little google search shows quite few news articles about China restricting access to content hosted on Edgecast last year.
As was already said above, tell the support about it.

That's right. Since the end of 2014 edgecastcdn.net is blocked in China. From then on the GOG downloader did not work anymore because it uses edgecastcdn.net as a download source. Since Galaxy does not work either, I suppose it also uses edgecastcdn.net as download source.

As for direct downloads directly from the website (cdn.gog.com/...), they were also blocked end of last year, just for a few weeks or so and after that worked fine again until last week. Now also dead. Hopefully only temporary again.

In the past I heard for such "special cases" GOG support is able to provide a FTP download option for affected users. But obviously this would only be possible if the number of cases is limited, not as a long-term solution probably.

received any reply till today ?

China's government is a disgraceful monstrosity that somehow manages to appease its citizenry by telling them. "Look here instead of fucking your arse with the metal studded strap-on I'm going to use one without, aren't you grateful? You'd better be, because if you're not I can always go back to the old one."

The scary part, it works.

They were pretty prompt in getting back to me. They tried to upload a copy of the client to dropbox for me but nope, that's also blocked in China. I was waiting for another reply but just got so impatient that I've signed up for Astrill for a year and got the game using the GOG downloader. Galaxy still won't update automatically though. I've been too busy playing The Witcher 3 to send my Galaxy logs to the guy that was helping me at GOG. :) This game has been eating most of my free time these days. Loving it.

I guess when you are in China, the best is not to use the Galaxy client but use a service like Astrill and download the games directly without the Galaxy client (downloader or else) and have fun playing.

It is a pity though. If the government in China is not blocking Steam, why blocking GOG. Maybe they have a PRO DRM stance.

They're blocking the CDN GOG uses not GOG itself.

But isn't the CDN of GOG not just cdn.gog.com or it is somebody else behind? Whom are they blocking exactly.

I'm Chinese myself but I find China are pretty retarded with their censorship. -.-

I mean, blocking illegal activities are fine, but Facebook and Twitter? -.-

Also, I should install dig on this machine.

Is it still true that asking of the Tiananmen Square protests of 1989 is still forbidden?

The downloader and Galaxy not working was all fun and games until the direct downloads stopped working too.