I actually don't mind Expedia. The last few months I had to change a ticket several times. Every time I called they pick up almost immediately. The service is a bit tedious with the usual "please hold while I speak to a real agent", and it takes some effort to make them pick a new itinerary. But they were able to handle it every time (and calling late in the day got me agents not in India, who were faster and more efficient).

By comparison the airlines that issued those tickets can't be reached at all (states 1+ hour wait on hold right off the bat when I call). So would not be able to handle this at all.