8023691177 I don't say anything when answering the phone. Speech recognition waits for a "hello?". If it's a real person, they'll say "hello!".
When I answered this call, and just listened, it eventually hung up (no background voices, no live person or call center). When I called it back, I was greeted with a pretty convincing robot. For a moment I thought "this could be a real person". But it wasn't, just an AI that had a few recordings at the ready to respond to a few words.
I didn't spend much time on the phone. Damn time wasters! I'd like to jam a live power cable into their back-plane and create some smoke.