These people fuck me off. They know exactly what they're doing, even if they are 'only' working for a "We believe you've had an accident" referral scheme.
How I deal with them depends on how much time I have and what mood I'm in - some times I just hang up with a brisk "Fuck off" and block, sometimes I like to play with them. I had one who told me I'd had an accident, and I asked if it was the Ferrari, the Lambo or or the Aston she was talking about. I ran through all of the many and varied accidents I'd had in them ("...and the Lambo I drove off a mountain pass in Tibet, swerving to avoid a family of tapirs"), and all the personal items that had been damaged. This included several tiaras of varying precious stones and a stuffed Sumatran tiger.
Other times I've just parroted back to them what they say in a silly singsong voice "We believe you've been in an accident", "We believe you've been in an accident!", "Hello?" "Hellooooo!", "Erm, Mrs Daffodil?", "Erm Mrs Daaaaafffoooooddiiiiiiiiiiillll!" That unnerves them quite quickly.
Or I just ask them why they do this job and tell to remember that they are being a shitty person in harassing people when they have no right to, and that they are hated for what they do. Mean, yes, but if they need money that badly they could go and stack shelves in a supermarket.