Posting in a thread has a much lower effect compared to pressing the "bump" button. As such, you should not worry about "bumping" a thread when you post in it.
One post from someone who earned a lot of Merit in the past year is to put a topic close to the top.
The solutions:
3. Create an alt-account dedicated to calling out scammers.
If it earns Merit, you'll need to create a new one.