TeamWave interview questions

I was looking for developer opportunities so contacted few companies on Angel List Within few hours I got a call, turned out to be TeamWave. It was an introductory call and the person on other side who is an HR was cordial. Also agreed for compensation and there wasn't much argument there. Little later I got call again asking about what responsibilities I can take. I agreed that I can take up some work apart from the role I applied to as well. There was mutual agreement. Immediately I received a mail which had two assignments. I was very excited since the company looked very positive and quite professional. I wasn't able to start the assignment for sometime and got a mail asking to acknowledge the assignment mail as well. This again looked like a good indication of company. I submitted the assignment shortly. There was another assignment as well so I started with that. The other assignment was in a framework that I wasn't working on and had a complex part it was taking time. The HR also mailed me asking to update on the second assignment which I did. One day I called to inquire about how my assignment looks. Surprisingly, the interviewer told me that my first assignment was rejected. This was surprising because I had duly completed what was mentioned in the assignment (you can see my solution at github - purezen/teamwave_assignment). To add to it, he said my second assignment is shortlisted. This was a shocker since the second assignment wasn't completed. I first asked him why I wasn't informed about the progress on my first assignment to which he didn't respond clearly. Also asked to give me feedback on that which he obviously didn't have and wasn't even willing to share. This very much looks like a time-pass attempt on TeamWave's end. Following me up for solutions to begin with and then not even sharing feedback on the process not to mention their bizarre 'shortlisting' where they select an incomplete assignment while rejecting a legit solution. What pleasure do you get out of wasting people's time?