If you bought the game on steam, you should contact steam. But to be honest I don't think you're entitled to a refund. Think what would happen if everyone who didn't like the game they bought wanted a refund. Besides, there are many reviews of this game on the web. Every one knows it's mediocre at best.
The PC version of this game is so disappointing I am at a loss for words. I know that Aspyr did the port, but I am contacting Aspyr, Steam, and Lucas Arts to inquire about a refund because this level of neglect is unacceptable for such a quality franchise, and Lucasarts is still the first splash screen for the game.