As a manager who has had interview and hiring authority for several companies, I can add a little insight. There have been times where I liked several candidates, and had scheduled one or two of them for follow up interviews, but then extraneous circumstances intervened and I wasn't able to hire them.
For instance, the last company I worked for lost a contract in the middle of a hiring phase for me. I needed to add a couple new people to my workforce and I had already interviewed all candidates, had made a short list of the people I liked and was planning on calling them back for another interview.
However, the regional manager for the company informed me that I several employees from the closed branch had shown a willingness to relocate to our office and that we should accommodate them.
That was that. I sent rejection notifications to ALL of the candidates and picked the two best employees from our closed branch to transfer to mine. I didn't tell the candidates why, nor do I really have to.
In other words, a dozen things could be going on behind the scenes that you have no idea about. It's not optimal for you, but it's time to take it gracefully and move on.