Actually, probably "something phishy". Having to call toll free makes little if any sense. What would you think if you were asked to complete a transaction on Amazon by calling in?

Unfortunately scams like these are on the rise. Typo squatters purchase look-a-like domains and wait for a user to land. They feed real time info during the search process and then process payment, or in the case you report, use alternative modes.

Perhaps contact your card operator asking if it could have been a fraudulent transaction.

BTW - I'd suggest that you search for Expedia (and actually for any property) on the comments site you used in your OP. Scores are systematically low. My understanding is that they're not aggregators, but they collect their own data. I suppose that few satisfied customers will go there to vouch for a service/brand