How to kill a troll

There’s plenty of ways to feed a troll. Having both been trolled and trolled I have learned that trolls will eat just about anything but there is only a handful of ways to kill them.
Thank
Thank them for spending their time on you rather than all the other things they could spend their time on. It is high praise to you that they would sacrifice something they will never get back, their time, just for you. They deserve your genuine appreciation.
Empathize
Empathize with the struggle they are experiencing or have experienced. They did not have a good experience. It’s really sad when you think about it.
I’m not saying to be condescending or have a superiority complex but if you actually think about it, the troll has had some difficulty which is causing their negative point of view.
Apologize
Apologize for the difficulty they are having. About half of people must be less than average intelligence.
The troll might be suffering from below average intelligence and that is not something they can easily change. Perhaps the thing they are struggling with could be made easier for people like them. An apology that things haven’t been made usable for everyone could make them feel better.
Compliment
Compliment them on their insights. They were thoughtful enough to have an opinion, and take the time to share it. That’s more than most are able to do.
Some people aren’t capable of having coherent thoughts but the troll has collected theirs and put it into a sentence you could at least understand.
Help
The troll might be trying to request help in a frustrated state but expressing it in an odd way. Offering to help them might shift their attitude towards their experience and situation especially if you are able to help them be successful.