No, in the US they're made by Hershey. Elsewhere its Nestlé.

Specialty stores that specialize in selling gas, maybe?

You can buy Hershey Kit Kat (made under license) in the US at any corner store, complete with artificial flavor. Nestle Kit Kat (the original) tastes better.

I've tasted both. Not much difference.

Hershey make them under license, but as with all hershey chocolate, they do not add milk or sugar, so it tastes horrible.

Quite the opposite. Hershey adds so MUCH milk and sugar that it's more of a slightly brown sugary mass than anything resembling real chocolate.

They use soured milk.

and corn syrup