ManageGo interview questions

I had an initial phone call and went over my experience in detail as well as answered a few questions regarding my previous sales history and tactics. They called me back to invite me for an interview in person 2 days from then; unfortunately I was driving and didn't manage to write down the interview details. They were supposed to send a follow up email with details but I never received that. I called back and spoke with Larry who apologized and informed me that the position was filled... Why call me the day prior to invite me in for an interview at a scheduled date and time? Imagine I hadn't called and just showed up for the interview they originally invited me to...? Very unprofessional, and a waste of my time. I'm glad I didn't drive out there to find that out.