It’s not the call to you that costs.
They want you to call them back, and they try to keep you on the line.
I understand.
When I called back, I got a very low quality audio menu recording. It never identified a company or organization. A low-quality recording of a female voice said something like "to access our services, dial one for bla-bla, dial 2 for..."
I disconnected the call right after the words "dial one."
I don't see any evidence of a charge resulting from my outward-dialed call.