Amazon Prime is particularly heinous about using dark patterns to confound users into risking forgetting but ultimately you’ve already paid for the month, year
I can confirm this to also be the case with most streaming giants plus the less-giant Shutter
Edit: comments have pointed out some notable exceptions such as services through Apple and HP Instant Ink
Any specific service you’ve seen doing this?
I’ve not experimented as much with cloud providers or non-American companies so not yet sure if this is a byproduct of industry practice, market pressures on public companies or legal requirements and counter examples could help
I should also point out the good: many of them (like Netflix) are very open about how cancelation works once one goes to that section of their site
All subscriptions through Apple do this.
The upside is if you cancel a yearly subscription after just one day you get basically all your money back.
Added
ClassPass
Trial cancellation terms (sorry anchor link doesn’t seem to be working)
Napster did this when I went to cancel. They said if you cancel now you lose the rest of the year you already paid for. I set up a reminder to cancel as the time got closer to the renewal, but the service was so bad I contacted customer service and asked for the remainder of my money back that it was unsuable for me. They finally ended up giving me a refund. There have been others, but that one sticks out in my mind.