I'm surprised people here still book with expedia. I recently booked with them myself after seeing them mentioned here many times, but not remembering in what context. This was an unimportant booking and I planned to take advantage of the supposed 24 hour free cancellation expedia prominently displays. Less than an hour later, I tried to cancel the booking, and it was like pulling teeth.
Apparently somewhere in their mumble-bumble they have hidden that the 24 hour free cancelation does not apply to "all" airlines. After an hour on the phone with them, including getting transferred to the airline in question by expedia, I just gave up. Not worth the aggravation for me, even when my job allows me to continue working while on hold.
Later on I out of curiosity checked trustpilot and see expedia has a rating of 1.2/5. I've never seen such a low rating for any company I've bothered to look up on trustpilot before, and I now understand there is a good reason for it.