HCL Technologies — Hr not responding

I have been selected for software developer role and also finished background verification. My hr who is incharge is not responding after that. I called him many times and also mailed him, there is no reply from his side. Please make sure somebody is aware of these things. People who got selection after me have already joined. I had even received a survey form which asks why i didn't join by now. Please change my hr to someone who atleast respond to the mails when necessary.