Tech Mahindra Senior Java Developer interview questions

I attended a walk in interview at the Hyderabad location. It was a day long process comprising two technical and one HR round. The technical interviews were straightforward, the interviewers covered all the standard Java concepts, followed by Spring and some web services questions. In the second round, the interviewer (a manager at Tech Mahindra) gave some details about the client and the description of the position. The HR round consisted mostly of salary negotiation (I was flexible with the salary). I was told that the HR guys would be in touch. It's been almost a month and a half now and there has been no news from the company. When I contacted them, they told me that they are no longer considering candidates for the position. I am not sure why a company would want to waste people's time and conduct a full day's interview if they are not interested in hiring them at all.