What should I do if my landlord refuses to return my security deposit after I vacate the rented property?

You may first like to make a try for an amicable settlement of the dispute about your security deposit with the landlord. If that does not bear fruit, you may serve on the landlord a legal notice for the recovery of the deposit. If even after that the landlord refuses to return the deposit, you can approach the Rent Control Court for relief and/or file a civil suit in the appropriate court for recovery of the amount of deposit with interest. Keep all records related to the tenancy, including the lease agreement and receipts, as proof.