It is very annoying when people contaminate the LFG chat with boosting messages. It is also straight up prohibited. Normally I would just /ignore people like this, but they keep creating new level 1 toons to circumvent this.
Please do something about it. Either enforce the law and ban people who advertise boosting in LFG, or make the LFG channel only accessible upon reaching a certain level.
As you notice…
Though they do get either character silenced, usually before or then switch to another toon/account to continue. Hmpf.
I recommend to use chat addons to additionally filter and quick report these.
They would just bot their way up to that level and nothing would essentially change.
I am sure their numbers will dwindle if they have to create a new account, buy subscription and level their way to a certain level every time they get banned just to make an advertisement
You can replace the advertisment reason with any botting reason like grinding mats for sale and you can see the botting numbers don’t get impacted much tbh.
But thank you for the reports and don’t forget the chat addons.
No offense intended, but are you also reporting them, or just ignoring them?
Becasue if nobody reports them, then they never get sactioned, just like the fire department will not come to your home sirens blaring and hose in hand if nobody calls them to say there´s a fire. 
I ask simply because it seems to me these days that most people, esp on fresh and SoD but also on retail and Era, do exactly that, they ignore but don´t report, then come to the forums or reddit or open tickets to complain about a problem they´re effectively not even trying to help blizzard stop by not reporting it. 
Bots are valuable assets, ads are just ads. Sustaining bots is worth because they are extremely lucrative. Dedicating the same amount of time and resources to run advertisement in hope that someone will follow is simply inexpedient
Are mutes not account wide? That seems like a pretty big oversight.