I bought my Wii on the same day at a Toys "R" Us and the bundle was not mandatory. I got it because it seemed like a decent deal. Little did I know that Ultimate Alliance sucks royally. You were lucky to get a different game.
I'm going to try and exchange Ultimate Allaince pronto. I gave it a chance, but couldn't get into it at all.
As for forcing you to buy the bundle, that's pretty much the definition of bait and switch if they advertised the console by itself before hand. The store I went to only had 14 and they were all bundled. If you didn't want the bundle then they just pulled they rubber bands that were holding the game and glova boxes togther off. I like the glove though. It gives you a good grip on the WiiMote, but mine isn't pink!