Very worst I got short listed and first they asked...

Very worst I got short listed and first they asked me complete case study and send it back after that they scheduled a interview call with VP and then they didn't even revert back.
When I contacted them the HR replied that you are not selected and I asked them the reason they don't have an answer.
Just they make use of the case study which has 2 email templates and they make use of our creative ideas.
Wasting all talented people's time in the name of case study and interview process.