Originally Posted by palmanfr

THEIR systems issued tickets based on valid fare rules. Those bookings were not results of a hack of any sort by someone external to AF/DL. Those bookings were done after someone from AF/DL published a change in the base fare. This was not the fault of the customer. The average customer would not know this (remember : not everyone in the world has a membership on Expert Flyer and is fully aware of the airfare pricing structures and marketing strategies).
Again, AF does not care if you make a mistake or not when you book your ticket and need to modify the dates. They do not care either if you show up at the airport too late or with an excess of luggage. They just charge you according to their rules, which you agreed when you purchased the ticket. A potential mistake was done at their side, too bad for them. Now man'up, "give me break" and take your responsibilities. And learn from your mistakes.