The issue with gold spammers in a game like this is they only work when people are buying from them. You can try and combat them but at a time with a buncha new players (Alot of which are possible gold buyers) the built in securities get overwhelmed since gold farmers have much more funding/resources/buyers.

However, keep in mind 99% of the time bans go out in waves. Meaning it will be terrible for awhile, then one day the world will go silent as thousands of accounts are banned.

Just ignore them for now, best you can do. If you have troubles with blacklist limit go ahead and clear it since gold farmers make new accounts every few hours to avoid targeting. You wont get whispered from old people on the list.