House owner deducted the extra amount from rent deposite

Hi All, I took a flat on rent on 8th July 2017.At that time they said that once you shifted in the home they will do the rent agreement(I deposited the 15k(rent)+40k(deposite) in his bank account).After some days when I asked for the rent agreement they denies for this.Also once I am shifted in the home I got to know that one room is having lots of water leakage & we didn't use that room(They didn't told at the time of renting out the flat).I told this concern & they agreed that they reduced the rent as 12k. Now I vacate my flat on 9th July 2018.(reason:They denies for the rent agreement for this fiscal year).Now I shifted to my new home they do the calculation in below ways. So considering all this, total amount payable by you is: 18000(3000 extra in rent month for 6 months) + 1482(Gas Bill) + 250 + 600(Cleaning) + 1000(Purifier)+7000(9 days rent) = 31332. So they transferred the [deleted] = 8668 in my bank account. This is wrong calculation & not acceptable by me.When I call them they didn't pick up the call & denies for the remaining amount. What is the way to get my remaining amount.