Private Owner of rented apartment review: Refuses to repay down payment 1

I had a lease agreement in place at the following location from 15th Jan 2011 to 15th January 2012. Since moving out the Land Lord has only refunded part of the security deposit and refuses to pay the balance
The appartment address is
207 River Valley Road # 09-64 UE Square, Singapore 238275
Security deposit was in the Sum of SGD 3, 300
I received SGD 2, 628.30 therefore balance of SGD 671.70
Please advise how i can get the balance of my money and the LL is refusing to pay.
The land lords email address is
LEE YIT KIAT [[protected]@SINGNET.COM.SG]