ZoomInfo interview questions

I applied online and a couple of days later a recruiter reached out to schedule a phone interview, and then was emailed to confirm the time of the phone interview, and that they would call me at the agreed-upon time. The time comes and no one calls. After waiting for 15 minutes, I sent him an email asking if he was still available and 30 minutes later got apologizing saying he got stuck in a meeting and asking to reschedule it for another day and the same happened again. Then I sent a couple of follow up emails and weeks later I got a response from the Senior Director who passed it over to someone else and the same happened again until they pass it over to another recruiter and never heard back from her. Out of all the companies I talked to, this was by far the worst experience I’ve ever had. The HR team is a complete mess and people there do not respect candidates. I've exchanged emails with 5 different people and even though we have scheduled an interview a couple of times, the first interview never happened. Extremely unprofessional, which is unfortunate because it looks to be a great company with a great product. If their HR is that messy and unprofessional, I can't even imagine the other divisions. I would not waste my time with them if I were you.