I thought I cancelled 2 months ago and I was billed this week. I went through the same steps and when I got to a page that said something like “confirm cancel” I hit it again.
The top of the page said “you have 364 days left to enjoy prime benefits”
This time I scrolled down and there was another box to click. A second confirmation. Such bs
This is an example of dark patterns. It can also include multiple steps to 'confirm' a decision, where the confirm button is beneath the decline button, only for the final step to have the button locations (or colours, shapes, etc) reversed. It's done on purpose to confuse people into giving up. Unfortunately, even if it works one time, it's justifiable for the company to continue the practice.
If you haven't used any of the benefits since its renewal, you can call to get a full refund. It did the same to me, and I was able to get the newest renewal fee back.
I cancelled two years ago and they renewed it somehow.
Then this year I let it use a cancelled card as the default and my one working card was on a list of 20 or so cards. It kept warning me that my card would not renew my prime subscription. Nah, they just ran an if statement over my cards to renew it.
I didn't really fight it because my family uses my prime video which has ads but I'm prepping them that it's not gonna be there next year.