Complex Creative Role interview questions

****Every creative people should be alerted of this company. **** It is a contract based role. They asked me to complete a ongoing project task which takes about a week to finish, and of course, without any compensation. I've been requested to present the most core, valuable part of the task. I mentioned this is impossible due to the nature of project, and my role as a candidate. They replied "We wanted to see your ability in certain aspect". It makes me feel very disrespectful and unreasonable. Since the role I interviewed is a short contract based role, there are possiblities that they trying to make people do unpaid work by the so-call guise of a creative assessment. Not to mention the workload is a bit massive for only assessment (hey they need a presentation not just few images could do).