Liars , cheaters, and users.

[Invision]

So basically there is a person who says they want to help you farm, and the moment they got their item they kick you from the group and move on. This person is known for this and would like to know if in fact is against tos so this person can be stopped.

Nothing more frustrating then people adopting this tactic and it's becoming more the norm day after day.

[Purrfectstorm]

It sucks that this happened to you but unfortunately the only recourse you probably have is to blacklist them and let others know about them. The community policing itself can have a powerful effect on that kind of behavior. You can also make note of people who you've farmed with who have NOT done this kind of thing and try to seek them out for future farms. That being said there's probably no harm in reporting to a GM anyway.

[SummonerSenah]

I've seen more often in farm parties people leave after they get what they want and you have to sit around waiting on another person to join the party. Seems really trollish for someone to get what they want and kick out people who still want to farm.

[vred13v]

not a perfect solution, but you could also make your own party, and hope whoever joins doesn't quit after getting their item