Blocked never a message

call saying they are on a recorded line.  I think they said medical specialties. When I asked why they were calling they hung up

This company (scammer?), calls from Ramona, CA. They appear to have at least 6 different numbers, so if you block one, they will use another. They hang up most of the time, and are as useful as a grass nat. When demanded they never call back, it's just like swatting at a hornet nest and they call all the more.