Most might consider it as spamming and its not always effective  - the best method is to get a thread for your case and notify them about it and also try as much as possible to explain everything that happened, add all evidence you have to support your claim.

Since you don’t know too much about the forum, then it would be best to first go through some scam accusation threads and see how they were created and the suggestions that were given one how to make it even better.