Unfortunately there is no way to clean and efficiently wipe RMT from the game. You implement features to block them they will come back. You can't ban IP addresses because a good majority of RMT bounce their IP's you cant restrict chat because it impacts new and returning players. All in all the real problem is the people funding RMT. Those people who buy Gil. Looking for the easy mode to obtaining gil.

I get maybe 2-6 tells a day about buying gil, not that bad honestly. It'll always be a problem the best you can do is deal with it cause no matter what a company does to block attempts The RMT just find another way to exploit it. Yelling at SE to fix something won't solve the problems and in fact there is very little they can actually do to stop advertisements other than hire people to sit in game and read chat 24/7 (who would want to do that seriously >.>). Just something you are going to have to deal with and if you are getting mass spammed from RMT, there is probably a good reason for it as they designated you a pretty open target. My Blacklist isnt even full yet and I been playing since launch.