Booking.com Customer Service Agent interview questions

First, it is a telephone interview then if you are pre-selected you are invited to the office where a team leader interviews you. The process takes approx. 1 month

The overall process was rather fast. I've applied online, passed their online assessment test and was contacted to arrange a short phone interview in a few days. At first, I've got an email with a suggested time on a Sunday which seemed strange but I accepted anyway. I was waiting for their call on said Sunday afternoon but naturally, nobody called so I sent them a polite email explaining the "misunderstanding". The HR replied on Monday confirming a new appointment later on that day without a single "excuse us for the inconvenience".... Well, I was then waiting for their call at the given time but yet again, 15 minutes have passed with no sign of the HR at all... Finally, with about 16 minutes of delay my phone rang: without even apologizing for making me wait, the lady on the other side of the phone stated the obvious that she was busy and in a hurry to finish with all the interviews. She asked whether I was still available or not then went on to whizz through the details... Asked me about 2-3 basic questions, explained that she had plenty of candidates for said position (which came off as if she wanted to make me feel as I was one of the "thousands of single use plastic cups"...) and answered my question about the relocation package (doesn't exist for customer service agents). I tried to stay calm and polite but man, was I furious! I then proceeded to write a lenghty but polite email to her and her supervisor (found on LinkedIn) explaining my outrage and how this situation should have been handled correctly (being busy isn't a sin but you must represent your company with your best behaviour at all times). This was a first for me. I've been to plenty of interviews in the past but was never ever treated so badly that I felt the need to express my opinion to somebody's supervisor....