I can live with some Amazon purchases, but I do find their pages quite confusing, and misleading. I made a large purchase from them just over one year ago, and without realising it I some how signed up to Prime. I only discovered this when I saw regular monthly payments on my bank statements. I chose to stay and try it, and I have to agree that their deliveries can be quite amazing. But I don't use it as much as I might, and as it was costing me nearly £120 I concluded I was not getting my monies worth so I decided to cancel.
I could not find an easy way to cancel, but the card they were charging it to was expiring so I simply let it drop, and eventually they told me the Prime account had been closed.