Maybe add a topic like : (in suggestion corner), so that it doesn't happen again.
Leave trade messages :
Suggestion : Remove the ability to erase trade messages. Let them be automatically erased in a week, or not, following user choice.
Reasons :
-Hackers trade heirloomed items then remove the trade messages, going unseen for the owner.
-It's good to keep in view who you've trade with, just to know.
And yes, speaking to admins on irc is the best choice. Click on the top right click on the forum screen.