Bonzai interview questions

The interview process was not clear enough, initially HR told that there would be an F2F and then a coding assignment round. In the following week they called me in for F2F interview. The interview was with one of the directors. Its was straightforward most of the questions were around system design. After a week I get an email from HR stating that the interview went well and they need documents ( salary slips, educational documents etc) for further process. After I sent the documents I never heard back from HR I tried to follow up on email but no response. I felt this was very unprofessional.