You don’t explicitly say why you think Apple should take action. You don’t say you own that trademark, or that doing that is against the license of your open source app.
Which of these is it?
> I reached out to Apple via their trademark complaint form a week ago. All they seem to have done so far is forward my complaint to the author of the scam listing.
What else would you expect them to do in that period? You told them “App X is breaking trademark Y that I own and I didn’t give them permission to do so”. They can’t take that at face value, so they asked for a rebuttal. A week isn’t too long a period to give them to reply, isn’t it?