When I contacted Roku about this issue it took a little time, and three separate support people, before they acknowledged that the channel had been removed. The last support person that I chatted with issued a refund to my account and told me that he cancelled my subsciption so no further action was necessary. I don’t know how long this would have taken if I had not contacted them directly.
There are your standard, public domain and **bleep** print streaming channels, or paying to watch classics on Prime or Vudu. There truly isn't anything as good as Chiller Thriller TV. I love Shudder, but the catalogue of classic and B-grade movies that Chiller had was amazing. It really sucks that it's gone.