Adconion interview questions

I was so excited to be asked to interview with Adconion in San Diego after hearing about the amazing work environment. After two grueling phone interviews and a three person panel interview at the office, I was asked to come back in for a final interview. When I didn't receive a confirmation for this last interview, I followed up with HR and was informed they were working on scheduling me to interview. I emailed about a week later to get the status of the position/interview, and the email was not answered. Then I followed up again a week later. And never heard another word. I had invested a good amount of time in the process with Adconion, and to have it end like this was really disappointing.