To our resident Ralph Nader, being "stern" means you are allowed to call them Nazis if they refuse.
Don't let him confuse you either as to the difference between "waver" and "waiver."
In most civilised countries you have rights as a consumer, but so do the companies who produce, publish and sell software. For every "innocent victim" who genuinely has problems with the product after numerous patches and tech support, there is someone who figured out how to get a pirated copy or who has already grown tired of the product.
If SEGA / CA / Steam technical support were unable to solve legitimate PC-related technical issues on a system that meets minimum spec, then you could have a case. If you could prove that the game was deliberately falsely advertised and did not deliver on one of its key selling points, you could have a case (presumably along with thousands of others). If you have a nice shop manager who is willing to exchange the game for another title, you will be lucky.
I am among those disappointed with this release, especially because of the technical and AI issues, which are gamebreakers for sure. Did they release it before it was finished? Sure. Did they pump up some of the features which don't work, yes. Are they deserving of a class-action suit? No.