So Asmodee takes over Catan from Mayfair, and then fails to offer decent support. So on Saturday night we opened my brand new copy of Catan Ancient Egypt and one of the blue "papyrus" boats is missing. So, I call Asmodee and they tell me I am SOL! (not in those words). I think it is very lame that they have NO parts for this game even though they are supposed to be supporting it. I apparently have no recourse and I am pissed off at Asmodee but then again who isn't these days?
I'm not a fan of Asmodée and have been pissed off by their customer service myself, but if they have never published that specific Catan game, why would you expect them to have parts for it?
Have you tried to contact Mayfair? They might still have parts and may be willing to help you, even if it's not their game anymore. I don't know if this has changed, but they used to have very good customer service (it has been a long time since the last time I needed it).
Part of the problem could be a redirect for parts requests. I had a similar issue with a Carcassone game. But Z-Man parts requests redirects to Asmodee. However, Asmodee responded by telling me I was on my own.