Hmmm... Yes you got a bad deal but you did not take control of things when they called you.
This industry prides itself on screwing its customers again and again. Marketing departments call the changes enhancements, I call it the shaft. Bearing in mind this attitude pisses off many people who call the airline, try being extremely polite not rude and propose your own options. Expertflyer.com is a great resource for available seats.
If one agent turns you down, call back, but be nice.