APA Agency Mailroom interview questions

A phone interview followed by an in person. Told me they'd follow up after initial call to schedule in person. Never did. Had to call multiple times. Each time the same response. WEEKS later finally get Interview. Told that a third, panel style interview is coming up and that HR will let me know if I will be going. I don't hear from them that week. Not even the day before. I hear back the day - of with a form email that I they are going with someone else. How am I supposed to prep on that schedule? Get dry cleaning done or save that money? Schedule work? What about standing offers and other interviews? A company that does not treat applicants with the basic respect that we show them.