(1) Save as an agreement to the contrary, it shall be lawful for the landlord to charge a security deposit equal to one month's rent. (2) The security deposit shall be refunded to the tenant within one month after vacation of the premises, after making due deduction of any liability of the tenant. (3) Wherever the security deposit is not refunded to the tenant within the period specified in sub-sec. (2), the tenant may file an application before the Rent Authority for directing the landlord to refund the security deposit.