What the company did was in extremely poor taste, so much so, that I wonder if there might be something more happening, especially since you said you bombed the interview, both technically and personally.
In your job application, were you truthful and honest? Did you lie or seriously exaggerate about your skills, experience or history? Was there a phone screen before the interview trip? Why did the phone screen go well enough to merit an interview then the interview went so poorly?
Basically, if you were not the job applicant you said you are: If you lied on your resume, or had someone coach you through a phone screen, and then were discovered in the interview, I think the company would have a real right to be extremely pissed off, and possible a legal right due to fraud to claw back some of their expenditures.
If you are confident everything on your end was honest and level, and you just had a really bad interview for a job that was a poor fit, then you probably have a strong legal case and the ability to create a PR and Recruiting Nightmare for the company.
If you do decide to make it a Public Relations / Recruiting Situation, you might consider making it about the individuals involved as well as the Company. Companies can be faceless, nameless, bureaucratic beasts, but if you name the HR-recruiter and Hiring Manager involved, and make them responsible for their own decisions, it might be more effective. Check with a lawyer and be careful to avoid unjust defamation.
Edit After awhile, another possibility that occurred to me is that this might be an effective way for someone from the company to embezzle money:. They look for candidates who have bombed, then cancel the return ticket, routing the refund to their own account rather than the company. The company wouldn't know that the candidate was left stranded, and whoever re-routed the money would have pocketed the cost of a refundable ticket!
If you have only spoken to one person at the company so far, who kept repeating the same "other direction" line over and over, they may be the embezzler, hoping you will just go away. You need to speak to at least a second person at the company, and get an acknowledgement that the company really did cancel your ticket. Otherwise, this may be part of a much more serious crime.