How do you file a complaint when "Roku Command" messes with your home page?

I don’t mind (too much) when Roku changes my home screen wallpaper to promote some new program that they are being paid to promote, because I can always reset my wallpaper back to the one I want. But  a few days ago Roku added a row of “recommendations” at the top of my home screen, and I cannot find a way to delete them. I do not care about any of the things being recommended, they have inserted themselves ahead of the three channels that I WANT to be the top row of my home page, and I am just generally annoyed that Roku has “taken control of my screen” (shades of the old Outer Limits TV show!) and left me no way to put things back the way I want them. And now I don’t see any easy way to “Contact Us” so that I can tell a live agent, directly, that I would very much like to have the freedom to delete these unwelcome “recommendations” and put things back the way I want them.

Ideas, anybody?