I have had a couple of experiences with not seeing the place to click to negate the auto renewal option.
The good news is that I use a virtual credit card for all of my on-line purchases.
It is called Shopsafe and is provided by Bank of America credit cards.
I go the the BOA site sign in and get a number that is keyed to my actual number but can only be once and for a time I specify. It is also time limited. I usually specify two months.
So if a company tries to auto renew they have to get in touch with me because the number is refused by BOA.
CitiBank used to provide a similar service but I don't think they offer it now. As far as I know BOA is the only one offering it at this time.