Invited to interview, which was organised promptly for some weeks later. Three days after organising the interview, I received an email advising that the interviewer was 'very busy' and that they would have to cancel the interview, however there was no mention of re-organising the interview and I never heard a response when I listed my alternative availability. I don't think it's difficult to inform a candidate that the role is no longer available, rather then saying that they’re cancelling due to the interviewer being too busy!