u never check the online itinerary sent to your email right after transaction, if u call them right after, they will help u make any changes on the spot.
if u wait until long long time, don't think they will help u
called within half hour!
the on screen booking information is different from the information you get in your email after the booking.
e.g. flight timing is wrong obviously.
booking on screen says A to B 0900hrs,
now email you get B to A 0945hrs
when this is noticed, call is made within half hour. Now the airline wants to charge ridiculous fee for the change, saying that is online promotion price. now they can only charge by their standard price.