Even though the individuals are humans, they are reading a script given to them by a soulless automaton (also made of humans, but the result of an inhuman optimisation process).

Those writing the script are taking advantage of your aversion to skip social graces when they decide what questions the low-ranking representative will ask you.

The only winning move is not to play. It's not the individual's fault, but neither is it fair on you to play along. Be polite, but direct, and don't play the game.

Right. But that just means company is wasting your time and manipulating you.

The script they have doesn't work anymore. If it's designed to make you stay it has backfired in spectacular way.

I tend to go with a few "No, thank you"s at first and then, if the heat picks up, the ol' firm & fatherly "Look, I appreciate it, but I'm going to cancel today no matter what," informing them that there's nothing they could do or say to try to make me change my mind and stay, ♫ we never did too much talkin' anyway, so don't think twice, it's all right.

Well, yeah. They're following a flowchart that labels common objections and the responses to overcome them. You're in a pipeline. Your job is to get to the end of that pipeline without being shunted off in long and meandering side paths.

Their job is to stop you from achieving your goal. They're a person, but they're not your friend in this interaction. You don't need to be rude, but you also don't owe them anything beyond basic courtesy.