Lease breakage due to neighbor harassment?

We signed a one year lease in CT. I have 2 kids (8&2year). We were receiving continuous harassment from our neighbour and he also threatened us by leaving a piece of paper in front of our door sayig that he will inform police or the DCF. We are very decent family and our kids usually sleep by 8:30Pm. We have also complaint about this to the police. But when the harassment turned into threat we decided to move out. We had informed our LL about all the incident as and when it happened. Finally we gave him one month notice and informed him that we may not be able to continue with the lease. He agreed and we meet him. After vacating he replaced the carpet and did some repair which went on for 20days. Then he advertised in the paper. Now after 2 months he sent us notice that we owe him rent till the apartment is rented. We have already paid him $2400 (last month rent and security deposit).Can any one tell me how much more do we owe if the apartment is not rented till July?