Shoutout to Shudder, a streaming service for horror movies/shows, that doesn't confirm payment at all besides making sure it's a real card.

I've been using 10minute email and a gift card with 13 cents on it to make free trial accounts for more than half a year work no issues

If you cancel the free trial as soon as you start it you normally still get the full trial so nothing to remember!

With Amazon at least you can contact them and ask for a refund if it's just one or two days after the payment, it has worked twice for me (genuine mistakes of mine)