Dear Khun Pornruedee kha,
According our phone conversation pls see the details as request kha.
However for IVR FORM if you already completed forms can be sent to the below address or by hand to Citibank at 12 Floor counter no. 2 There is box of CititService for send document to CitiService kha.
Citibank N.A. Attn CitiService Unit
18/F, Interchange 21 Building
399 Sukhumvit Road
Klongtoey Nua, Wattana
Bangkok 10110, Thailand
Should you still need further information, please don't hesitate to contact CitiService at Tel 662 896 3100