Amazon Non Software Development Engineer interview questions

The first round was okay, I applied through my college job portal and was asked by mail to schedule a phone interview. All the questions asked were basic and I passed that round. I was asked to schedule a second interview and when it was time for it I was prepared and all but did not get a call, I mailed them inquiring about the interview , they apologized and rescheduled it. This time I received a call. They asked about Java Generics and Dynamic mapping etc. Later programming question was about finding repeated alphabets in a sequence. They did not like my logic and approach to the program.