I have to wonder if they actually did an upgrade without your permission or if the renewal price was just such a jump from the introductory offer that you thought that was the case. If it's the latter, that's why I always tell people to check what the regular rate is before signing up for cheap promotions, since I learned it the hard way.
I don't like the auto-renew thing. They did mine at least a month in advance, which I wasn't expecting. My bad, I guess, but I didn't even know they would auto-renew without contacting me. I planned to shut it down right before the renewal would come up, but it was too late. I wasn't happy about losing that money.
I will definitely read all the fine print more carefully in future endeavors. I will also be sure that sites don't save my credit card info or remove it myself.