Purplex Marketing interview questions

Invited to interview, which seemed positive. Was invited to complete a 300-400 word blog writing task for a fictional client, submitted before deadline. Heard nothing for about a week, then received a cursory email from one of the interviewers saying they'd "filled the post internally, thanks for the blog, it was a really good read." No other feedback despite requesting it. Six months later, that job remains advertised on the company website.