I have applied twice to two different positions at the Corporate Headquarters and had the same experience in both cases. My first time was in 2002. I had a phone interview first and then an in-person interview. After the interview I followed up with HR and the Hiring Manager several times, however they went totally silent. No e-mails or phone calls were replied and after a few weeks I just assumed that I didn't get the job.
10 years later I thought I'd give it another try. I applied for another position in mid 2012. I was contacted by the hiring manager (department head) and received an invitation for a phone interview. The interview went great and this time I thought I'm smarter and asked during the interview what the next steps are. I was told that I will definitely hear from them again and that there's great interest. But the exact the same thing as 10 years ago happened again and they went totally silent. Any follow-ups via e-mail and phone remain unanswered.
An interesting fact is that I received a call many weeks later from somebody I know who works there and asked if I can recommend someone for another open position that they’re desperately trying to fill. Unfortunately I couldn’t recommend anybody based on the recent interview experience, unless of course somebody is really in an urgent need for a job.