Because the original design, the one you claim was "inspired by" your work was in actuality significantly different than the examples you showed. If it had actually been similar I would agree with you. But it wasn't. I'm sure to you it looked very similar but to the rest of us they were clearly different patterns and designs. I'm sure it must be very tempting to look at a square or a triangle and think that such a pattern must have been "inspired" by the triangles and squares you made, but how else do you build one of these without making little geometric shapes? Maybe selfish was too strong of a word. Maybe pretentious is a better fit, since you obviously drink your own Kool-Aid and aren't just being malicious.
Consider another item, like a car wheel. Do you think that every 5 spoke wheel looks the same? Is every 5 spoke wheel inspired by the very first 5 spoke wheel ever produced? Should the first maker of a 5 spoke wheel get license fees from every 5 spoke wheel that came afterwards? No.
But the surprising thing to me, is you could have taken the glory here. But you threw it in their face. You could have had a piece of art that was publicly "inspired by Victoia Balva". Most artists are flattered to have their work inspire others. They don't usually see it as a missed revenue opportunity like you do. And when they get what they want, they usually go home happy. You didn't do any of that. You tried to force them to commission you, pay you license fees, and when they decided to just stop being inspired by you that also wasn't good enough. The ONLY way to make you happy here would have been to keep the "inspired" design and pay you to use it.