NVIDIA Salesforce Developer interview questions

I got a call from HR. He asked me for suitable schedule for telephonic discussion. We agreed for a slot. No sign of call after 25 minutes the time of interview, when I called HR and ask him to remind interviewer. He asked me wait for 10 mins and I waited another 20 minutes without any response. I again called HR myself and asked him to reschedule as I was getting late for office. HR told me that he is going to reschedule. But again I did not receive any for a week. I tried to contact them via phone and email. But they didn't response any of it. My message to recruitment team. Forgot professionalism, get some courtsy first. Most terrible experience ever.