Shouldn't monthly condo fees be pro-rated from time of unit closing?

I closed on my condo on November 7th 2008. The builder paid 2 years condo fees at the time of closing. Now the condo association wants to collect for the entire month of Nov 2010. I believe this amount should be prorated, minus the days I did not own the condo, which is 6. All other expenses are prorated, taxes, insurance, phone, electric, cable etc.,why not this? Am I legally responsible for the payment of dues if I did not own the condo for those 6 days? any feedback appreciated... thanks