dmc digital media center Java Web Developer interview questions

After I applied through a website, they asked me to send my diploma, certificates, salary expectation, etc. on email. After that, they asked for a Skype interview. The interview time was not a suitable time for me as I had a conference and I asked them to change the time, they didn't respond to my email. I decided not to attend the conference and waited on Skype for their call. Nobody called me so I called someone from HR and told her about the situation, she told me that she found the interviewer and excused because of the situation. The interview went very well with the manager, I answered all the technical questions correctly and the manager said he will give a report about me to director. One week later they send an email that says "Thanks for the remarkable interview, but we will not go on with the process." I asked for a feedback but again they didn't respond. This was totally waste of time, I cancelled my conference because of this and I was rejected for an unknown reason.