SAT Practice Test #9 - Essay not Off-topic

When I took the optional essay for the SAT Practice Test #9, the prompt and essay was regarding the  passage "The North West London Blues," which is actually from Practice Test #7. I had written my essay in response to the prompt and passage that is about "The North West London Blues", but I got a score of  0 because it said my essay is off-topic. How do I get my essay to be properly evaluated? Thank you.