Ecowiser interview questions

They send an assignment through email to many candidates and give a deadline of 5 days to complete it. I completed the assignment within 3 days and afterward received a generic rejection email saying that my application was not selected. They did not provide any proper feedback on the assignment; instead, they just sent a generic rejection email. This is very demotivating. If you cannot give feedback on the assignment, then why do you send the assignment in the first round? Have an initial phone interview and then decide whether to give the assignment or not. Rejecting without any feedback is seriously demotivating. I did a lot of hard work to complete the assignment, and receiving a generic rejection email for this is seriously unprofessional behavior.

It was kinda of not easy because it was my first time of hearing such question but they require to make a research and do some interview on some clients to gain user persona and come up with a wireframe and design