Kylvan: I've tried to reach Focus on their Discord, radio / silent.
Well, it's the weekend...?
Seriously, though: We all know that some devs are absolutely terrible about patching their games on GOG. A few don't even update their games for years and GOG don't do anything about it.
But in this case, we're talking about the GOG version not receiving a patch that was released at 5 pm on the previous day, and a Friday at that. For all we know, Streumon/Focus Home might even have sent GOG the files in time, but everyone at the GOG offices had already left for the weekend.
What I'm saying is: If you feel this delay is reason enough to demand a refund, it's your right to ask for one. But I would encourage people to wait a few more days to see if the patch gets released next week. If it isn't, that's a much clearer indication that they don't care about GOG customers and you'll still be within the 30 day refund window then.