Car hire company cancelled the booking due to an authorisation issue, then booking.com refused to refund the cancellation and tried to claim it was due to customer issue - late pick up. Europcar confirmed that had nothing to do with the cancellation, but booking.com claimed since it said in their own (not europcars) terms and conditions that you must arrive early for bookings the entire charge for the hire was forfeit.
When booking.com was contacted to resolve the issue, the first web chat agent claimed they would offer a refund as a gesture of good will only if a new booking was made, again with a europcar company - which was asking for another issue. After 2 hours passed with numerous errors and mistakes from the agent, when a request to be transferred to a supervisor it was claimed at one point that they dont have supervisors, then that a supervisor could only be contacted if the europcar branch could confirm the actual reason for the cancellation. Finally the agent terminated the chat without responding to the last request for a supervisor. A second agent was connected to who flat refused to pass to a supervisor.