I got a response to my email just a while ago!
It might be a coincidence, but it feels the way to contact them is to write to this forum :-) As for @_Patrick_, I got an answer within 24hours of writing here.
It goes along those lines: The order system was down and my order ended up somewhere in limbo. They did take the responsibility for this, would ship today and offered to charge me nothing for the accessories.
I can absolutely understand an order system failure can happen, yet the impossibility to get any kind of response back is the frustrating part.
As a side note : This is actually the first time I actively wrote to an internet forum, I used to think reading them is enough. "Boy, was I wrong" ... It was really every post that gave me new insight, angle, or a information I wouldn't figure out on my own. Thanks @Unventor @Seba @Chriull @Kalmar !