situation regarding rented house

I have rented 2bhk flat in Krrinaem and I am supposed to move in this house on 1st september 2013 and Inspecation is due on 29th of this month.Menatime on 1st of august window sill of window has come off and lying on th ground form 3rd floor and window can fall down either way.
I have signed the contract thought agency and I tried many time to contcta the about the status of apartment but they are not replying.I also sent registered latter to the agency but useless.
I ahve to move in with my child and I have already bought al the furnitures to move in and now that house is dangerous.
I dont want to break the contract.I really wnat to move in but I want it to fix before we move in..
as the day of shifting is coming I am panicked what if they donot fix???where would I go with my stuff??
please advise what I can do in this situation??