AMS Researcher interview questions

I applied via a third-party Recruiter for an Internal Researcher role with AMS. Having completed three telephone interviews (all an hour long), I was then invited to an interview in London. Following that interview, I was invited back a week later to London for a second interview. The interviews were fantastic and largely informal. The recruiter then informed me that both interviewers were really supportive of me and wanted to progress to an offer. However after several weeks of waiting, it transpired that senior management at AMS hadn't signed off on the position at all and the post never existed in the first place. I cannot understand how a company like AMS can go through a process like that without first getting sign off on the role existing. A complete waste of my time and several hundred pounds in travel costs (which are not reimbursed).