Did you sing them a few bars from the 4-letter word song?
My parting words would be something along the lines of:
"I hope you like bad press, because I happen to be a member of a really influential community website (is that safe to assume?) and I will WARN all other members to pass along my warning to others to avoid your company like the plague!"
Don't know if that will have any impact, but it will definitely make YOU feel better.
Or better yet, send them a bill for the cost of the fees, and claim it is for "Mismanagement of your investments"
They call it a "compensation for a loss to the fund" when you cause them to lose money, so why shouldn't you be able to reciprocate?