I think you need to put yourself in the landlord shoes to understand this situation. Remember, every time a landlord gets an agent to rent out his unit, he needs to pay the agent 1 month rental as commission, which is why most contract requires the tenant to stay at least 1 year. Unless you can help the landlord find another tenant to rent his place, without the need to engage agent again, then maybe you can nego with landlord to waive your deposit.