So what exactly does it say in your warranty contract? In this below-
.....what are they saying, this tuff above isn't covered? If so then I can understand bulbs and sealed beam lights but how are lenses not covered? I guess if you had a rock hit one of your headlights, that would be an insurance thing but either way regardless, even if you had a sense that was getting real weathered, I could see that not being covered and how they could say that's just normal wear like a tire, brake pads, or bulbs but that LED panel is part of the headlight assembly just like all the other electrical components that makes the whole headlight work. Besides, I don't see how they can even consider an LED the same as a bulb anyways because its not even a bulb at all. There's not even a filament in it.
I see that you've already told them to replace it on your dime but I would've kept trying unless you can find where it explicitly says that the headlight assembly or even the tail light assembly just purely isn't covered and if they still said no, I wouldn't have spent over a grand for just one headlight because you can find something way better in the aftermarket and two lights for that price.