Siemens Developer interview questions

I was called for Technical interview at Siemens(Electronic city) after clearing the first round which was an online test.After waiting for 1 and a half hours i was called for my interview.The interviewer was very polite.He asked me questions from JAVA and gave programs to write.I cleared the first round and was requested to stay for the managerial round.Due to some problem the round didn't happen that day and I was called for it on another day at 8.30.I went for the interview on time and waited till 4 pm in the evening because they couldn't conduct the interview.However at 4 pm I was called by the manager.He tried every possible way to kick me out.He asked three questions and I was able to answer two of them.However I was not called for the HR round later on.

It was a phone interview. Asked general questions such as Tell me about yourself. Everything went well. But it was a reject after few days. Can't figure out the reason :(