how to get out of Royal Elite timeshare?

My wife & i bought into a vacation club whilst in Mexico October 2011. We stayed in sandos caracol resort & signed contract for royal elite. We've found out in the last few months that availiablity of resorts that we require are very limited (sales person shown us extensive range of hotels)flight deals are no better than booking myself, I feel this is going to be costly in the long run, not the ideal deal that was sold to us.