This used to be the case with NYTimes, several years ago. But, I think it has improved. Same horrible experience, a few years ago. Then, I resubbed after a couple years. A few months ago, NYTimes ran an article on "dark patterns." So, I attempted to unsub -- it was much easier.

But, that is only the NYTimes. My guess is that the original hypothesis holds true for others; I doubt JFax has improved.