Landlord not returning deposit , not replying to e mails.

Hello, We have entered an 11 month lease agreement, for the second time with our landlord. According to the contract we sent an intent to vacate two months prior to the end if our agreement. In the beginning of the last month of our notice period, the landlord called us and proposed an extension for 2 months. He agreed to deduct the remaining rent from our deposit. So, wedid not pay the rent for the last month.Anyway, time passed and he sent us an email at the end of our notice period that he will not deduct the rent from the deposit. Now we are in the house, for one month, without an agreement. Our previous agreement stated that until the deposit is returned to us, we can occupy the premises, rent free and that the landlord will owe us an interest . So we haven't paid the rent for thus month as well. The deposit is six months rent. The landlord now asks us to vacate the house and only then shall he return the deposit. He has also threatened to disconnect our electric and water supply. He does not reply to our emails anymore. What can we do? Thank you for your help.