Arm Engineer - Computer Vision interview questions

This was by far the worst interviewing experience I've had in my life. For some reason, they never gave me a fair chance. Let me shed some light on the matter. I was initially contacted for a phone interview. At the scheduled date and time nobody called. I had to write to HR to ask was this about. They replied the next day, rescheduling my interview. The next time same deal, no call, no prior warning. This embarrassingly unprofessional behavior went on for 4 times. Yeah, exactly, 4 times in a row, nobody contacted me in any form and I had to write to HR each time. It felt like I was begging them to even consider me for the position they contacted me for in the first place. On the 5th time, I actually got my call, everything went smooth and I got to the Skype interview. Now, let me stress this, the interviewer himself told me at the end of the Skype call that I managed to answer correctly each question (without me even asking about my performance) and that I should expect a call within 3-5 working days. 3 weeks pass, no answer. I write to the HR rep that initially contacted me, I get no answer up to this day (this was 2 weeks ago). Then, I contacted another HR rep that was cc'd in an e-mail I received from them. She told me that she would try to establish the outcome of my interview as an urgent matter and apologized on behalf of the team for giving me an inaccurate timescale. After that, she came with a negative answer and asked me for feedback. I told her about my experience (4 times in a row no call) and the positive feedback the interviewer gave on my performance and she said she'd contact the team and come back with a call the next day regarding the details of this whole mess. Needless to say, that was a week ago and I haven't received any calls or messages.