Netcracker Technology Software Development Lead interview questions

The interview process was fine. I had two rounds in a span of 3 days. The first round was technical and the second round was director's round. It went fine. We even had a salary discussion and I was told that I am selected and will get offer letter in a week. However I did not get any communication after that. I dropped a mail to HR for an update but I did not get any reply, which I believe is little unprofessional on their part. Any professional will understand that there are multiple factors during interview. Sometime there is a requirement freeze, and they cannot hire the candidate. But it should be communicated to the candidate. More so if you have verbal confirmation about selection, they should inform incase there nis some issue.