他：hello miss chan xxx xxx, this is xx calling from citibank.
他：first, i do some verification with you before we proceed further.
他：may i know what is your ic number?
我：wait, how i know you are from citibank?
他：or miss chan, can you tell me your address please, this is for verification purpose only.
我：may i know what is it regarding?
他：sorry i cannot tell, but we need to confirm you are miss chan xxx xxx before we can proceed further.
我：perhaps, you confirm you are from citibank first, as your number appeared in my phone showing "unknown".
他：its up to you miss chan, you may call citibank to know what is happening.
我：ok i will, but please advise me what is it regarding so that i can refer to the right dept.
他：sorry miss chan we cannot tell.
怎样？我就是很怕 unknown number.