Here's what happened:
When we fill our cic profile, the cic website asks you how much money you will have to support yourself in Canada or whatever. There I entered the money just above the threshold (I entered 12,400 here), so that even if I have 20,000 , it's at least over 12,400. If i had entered a higher amount here, say for example CAD 14,000, (which is the actual amount I had in my bank, (INR 700,000) ), then the fluctuations would have come into play.
So I entered on the cic portal that I would have at least CAD 12,400 , and in the proof of funds and the bank letter which the bank manager verified, printed and signed on the bank letterhead, said that "This is to certify that Mr Pawan Kapoor with account number XYZ has been holding a savings account since July 1997, etc etc and has a total credit balance of INR 7,01,491"
This amount is approx CAD 14,000.
My father withdraws around CAD 2,350 leaving CAD 11,673 in the bank when the CIC agent checks (in my opinion he does most certainly check and verify from the bank) and I get the rejection.