US Defense Intelligence Agency Special Agent Polygraph Examiner interview questions

I was called and asked to pick a date between this date and this date for an interview. I gave them the date and they told me they would call me back to confirm. Two weeks later with one week until the date I gave them, I called them and asked them if they were still going to interview me. They told me that according to my HR file, I was only available on the date I gave them and they were interviewing on a different date. I told them that I would come down on any date they needed me to but that was not the question they asked me. They admitted that someone dropped the ball and they will get to the bottom of it. I called a week later and left a message but I never received a return phone call and my status in DIAJOBS went to nonzelect.