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.