Can't unsubscribe from a channel I never subscribed to

Every now and then, I randomly find channels in my subscription feed that I've never visited, nor have I ever watched anything related to them. This time, the channel doesn't even have an unsubscribe button so I can't get rid of it. How do I get around this?

https://preview.redd.it/y1uojqohwksh1.png?width=1740&format=png&auto=webp&s=4572a415d149f2389a3c0f900476a69c9c7aa387