Sometimes you have to wait up to several hours for a new game to appear in the library. Maybe you just need to wait a little longer? Unless too much time has passed...

I would be very grateful if someone can gift me Resident Evil 2

https://www.gog.com/en/game/resident_evil_2

Expeditions: Rome DLC is now on sale.

https://www.gog.com/en/game/expeditions_rome_death_or_glory

So as Realms of Antiquity =)

https://www.gog.com/en/game/realms_of_antiquity_the_shattered_crown

It's been like 8 days. I have no idea why this patch of Amazon keys is causing GOG's key redeeming system to just crap itself, but apparently something broke.

Hey hey !

Check your orders tab.
Did your game listed here ?

If so - did you try to refresh account ?

Well, it's not listed under orders even though it said redeemed when I did it, so I guess it somehow didn't go through?
How do you refresh an account?

Then you simply weren't the first to redeem those particular codes, and shouldn't expect to receive the game from them. Nowadays, during heavy load, GOG simply shows the same "redeemed" message to everyone who tries to redeem a code which is valid and hasn't been redeemed yet, adding the attempts to some kind of internal queue, and only honoring the first one for that code when they get around to processing it (0-12 hours later, depending on just how bad the load is).

Oh is that how that works? Well that's unfortunate then.