I just checked the email conversation with the vendor. The vendor first said that they rarely get reclamations about FK, but later added that whenever they do get problems, FK is by far the hardest company to work with. He also said that the contact person at the FK is very unpolite.
And just to be clear, after the vendor WAS turned down by FK I contacted them and reported what had happened, suspecting some kind of miscommunication. But they just said that their knives arrive by the thousands and therefore if one were to be faulty, they would all be. I really have no idea how they are manufactured so I could not argue that point by knowledge and do not think it would be fruitful.
To be clear, they did not admit that I had a faulty knife, they just claimed that cutting 0.5 to 1" (1,2cm to 2,5cm) pieces from branchless birch was being too hard on it.
The vendor replied to this with: (translated) "...Nevertheless, this kind of knife should be able to handle freaking native birch! We will refund this to you and sort this out with them"
I asked him about 6 months later for any news about it and he said it is probably staying at the shelf.
Apologies for not sharing some information right at start, I hope this clears out the matter.