Just to explain this unfortunate event a bit. GOG gave away "Mount & Blade" as a freebie as they did with several other keys. The key said that it will not expire and that was probably when it was donated to this giveaway. However some of those keys secretely DID expire (there was an uproar because of this) so GOG decided to give those people another chance but again the time was limited. Obviously you got one of those once "never" expiring keys which now finally has expired for good. What I want to say with so many words is that it was not zeos intention to give you an expred key and usually they aren't.

I'll email support and see if they'll be nice enough to help out since I missed that.

I will see if I can find the thread in which GOG explained the situation.
Edit: of course sometimes support is nice and they help you anyway. It's at least worth a try.

It's not a biggie. Thank you anyway and thank you for the explanation.

If they can't, I'll buy you the game since I feel horrible you got your hopes up.

No, please don't do that. Thank you for the offer but I've got enough to play.

It'll be on sale again and I've got someone willing to feed money into my wallet account when I need a refill.

Thank you again.

I have Fantasy General gift key in my orders list either. And the redeem deadline has ended. There is a post somewhere in this forums which explains the whole situation with Fantasy General and Mount & Blade keys (maybe others too). But I can't find it. The last day when you could redeem this game was like July 15 2017 if I recall correctly.

They could change the text from 'not yet redeemed' to 'expired'.

I just found the thread regarding the expired keys inclusing GOGs statement:
https://www.gog.com/forum/general/gog_is_invalidating_gift_keys_wich_have_a_never_expire_limit

Yes, this is it. The deadline was July 17th. I have been near the truth... Heh.

Okay, please remove Eador and Fantasy General as those keys have also expired. This is my fault entirely, I should have doubled checked these codes knowing that GOG has expired keys out in the past that didn't have expiration dates (I had thought they were done doing that, I was wrong).

May I have NEO Scavenger?

May I have Expeditions: Conquistador?

Can I request a Free Puppy? I only accept mongrels, no overbred/inbred dogs that are bred without regard for their health please