Bloomberg Research Scientist/Machine Learning interview questions

Unprofessional Interview process. Cleared the telephonic round but had to wait for a month to get a mail about the next steps. But they never scheduled the onsite rounds. Despite repeated mails no reply. When I mailed the HR manager I got a reply that the person incharge left the company and hence they could not schedule. Waste of time! Why do you do phone screen if you cannot handle the entire process?