A month ago just before departure at airport I realized that I have booked a ticket with the wrong date. I have no other choice but to pay the price difference plus $100 ticket change fee which is $881 in total.

Today I was browsering this forum and I see someone saying "rebook a ticket with same routing but different date would incur no fee". I am very positive that the two tickets has the same routing. I would call them up or write a complaint to them to ask the $100 back if this is right.

Thanks for any help!