ADP Product Management interview questions

Interview process was straight forward, the recruiter and his manager contacted me via phone and setup a phone followed by a face to face interview with 4 managers. the process was overall fine, but the after the interview as if they all vanished from the face of the earth, no phone or email even after multiple email sent. Absolutely unprofessional attitude, at least have the decency to inform the applicant the result or feedback of the interview, as if the whole thing went in a blackhole. if this is the professionalism of the HR team good luck with the rest of the company.