You should consult an attorney or legal aid for a complete answer. If you signed a 1 year lease, you will have some liability. You can not just cancel a signed contract. The landlord is obligated to try to re-rent the apartment. You are obligated to pay for the loss rent during the time the property is not rented. It may take a month to find a new tenant. While it is mean for the landlord to call your child's school, it is not illegal, especially if you were moving to that address to get your child in to a particular school (and you told your landlord that information).