In my experience it's usually a 2-step system. I get a spam call frome either a robot voice or someone with a heavy accent. This company is generally not based in the US. After collecting some basic information like your name and eligibility for Medicare, they forward you to a US based company.

I'm not a lawyer, but even though the foreign scam call company illegally called you, I don't believe the US based company is liable for anything because the scammers make you agree to be transferred to a Medicare licensing office.