Deloitte Senior Analyst interview questions

The interview process spanned for over 3 weeks and involved 2 stages of interview. The first round of interview was carried in a more professional manner with discussions around experience and problem solving techniques. Within 2 days of first round I got an offer and date of immediate joining but when I asked for the formal offer letter, it took them 10 days to respond and then on one fine day they said that there will be another interview based on some case study for which you have to make a presentation. For the 2nd round of interview, my presentation was pretty well explained and jazzy just to add that kick to the presentation. On the day of presentation, the interviewer never asked about any presentation and started asking about direct questions about the case study and I was never given chance to show my presentation. Further, the kind of answers they were expecting to the questions put forwards were so petty and immature which ideally would be expected from a high school student and not from guy with 7 years of experience. Then as expected, the next morning I received call discussing about not to go ahead with the offer. To mu utter surprise I asked about as to how come the offer was made based on the 1st round of interview, for which the HR person explained as a technical glitch. Hilarious.......