If you're so obnoxious that they go away, they might not call back to cancel again for a few days, and maybe that means you can charge them for an extra month. Or maybe they just give up all together.
Customer retention strategy for assholes basically :)
That's the incentive for the company. The incentive for the rep, presumably, is that they get paid a commission based on how many cancellations they prevent.
Customer retention strategy for assholes basically :)