Domande di colloquio presso Appsoleut Coders

After my first round of interview, I was asked to prepare a Game Design Document for a game they are planning to make (they gave this assignment to check my skills) I've spent three days working on it and made it as extensive and polished as I can so that it matches the high standards that I set for myself and I submitted it on time but there was no response from their side, tried calling them few times, they didn't pick or call back but searched for my name in Truecaller after not attending the call and didn't respond to my mails as well. It's been more than a week now. This is not just unprofessional but fraudulent of them to ask an applicant to generate ideas/pre production materials for a game that they are planning to make and then not even get in touch with them to inform about their decision.