Lawyers Of A Famous Brand Demanded I Changed The Logo Of A Personal Project, So I Did. But They Won't Relent.

So I won't mention the lawyer firm nor the brand in question for obvious reasons. But for a personal web series I made, the brand demanded I altered my logo, so I did. Months later they want me to scrub all videos and images that featured it online. Unfortunately that's not feasable, as we're talking about over a hundred videos and other hundreds of posts. I've spoken to local lawyers and they've told me a variety of things. As I'm looking for a range of takes here, What do you guys think? It's noteworthy that they haven't claimed anything about the content itself infringes their copyright. Neither does the name of the project. Just the logo.