Right on! you may have to pay

the fare difference too. For example, if the fare for your new time is higher, you might have to pay the difference between your old ticket fare and new ticket fare. Many airlines also charge transaction fees $75-$100 for any change, in addition to the fare difference. Not much youor Expedia can do at this point. It's the airlines' rules.

I have to say Expedia is pretty good about making things right if it is their fault. In this case, don't think it's their fault.