"In my case I tried to cancel a subscription 30 days in advance recently (nearly 1K per year). It turns out you have to cancel 90 days in advance but not more than 120 days in advance?? So now I'm on the hook for another 1K."

I believe you can put a stop payment at the bank. At my bank they charge $30. When the creditor calls the bank, they will read to the creditor the reason you are not paying.