Irctc — over charging from the amount

Address:

Mumbai City, Maharashtra

I Vivek Verma booked premium tatkal ticket transaction id [protected] for 2 A.C from Bandra Terminus to Lucknow Junction for myself vivek verma paid through ICICI credit card via ICICI card gateway . During payment final amount was 2790 Rs + taxes.So i proceed for pay now option but when i got ticket irctc charged 4980 rs + sc- 22.47 + pg charges so total Amount charged through credit card was Rs 5002.47 . So i tried to cancel the ticket because ammount charged was much more then showed on screen. & my ticket got cancelled but the fact that premium tatkal tickets can not be cancelled after booking . When i asked for extra ammount charged with customer care of IRCTC at Delhi on Customer Care No.[protected]. she told me that the ammount showing to your screen at time, pay now option, that will be charged but extra charges deducted because of delay from bank icici which issued late OTP.As per IRCTC, bank is responsible for extra charges. When i contacted ICICI bank Customer care [protected] they told bank had paid only ammount which was forwarded by irctc site. i saw ammount 2790 + taxes for ticket but i got very late OTP. Why bank delayed OTP, ( and why 3d security password option not there for pay where as for normal tickets 3d security password option showing ) when i already have 3d security password and because of delay i charged for extra ammount . So my question is 1) how the change in charged ammount happens and when i agreed to pay some amount for ticket so how irctc can change that ammount after my confirmation for previous ammount & 2) why bank delayed OTP AND why bank send OTP if i already have 3d security password for online transactions which is faster then OTP option bank has to pay me back the extra ammount charged. waiting for an early response.