I went through this exact nightmare with my aunt's estate last year. She subscribed to everything! I had a spreadsheet going just to track who I had called. I remember spending a whole morning trying to find specific contact details, like searching for the
guideposts phone number because the contact info wasn't clear on the renewal slip. It’s tedious, but calling is definitely more effective than emailing. Once you get a human on the line, they can usually flag the account as "deceased" instantly, whereas emails seem to get lost in a generic inbox queue.