Not sure what country you're getting angry in, but in the UK at least, they "officially" changed the pronunciation from "hyundai" to "hyunday" with a series of adverts a couple of years ago.

They were literally called Hyundai (i.e. with high-un-die pronunciation) in all their own adverts and everything for the last 40 or 50 years. Of course, basically everyone still calls them Hyundai.

I don't think ignoring a companies "rebranding advert" really suggests anything about someone's knowledge or care.