Don't need lots of resources, just enough determination. Asterisk and a TTS (https://medevel.com/14-os-text-to-speech/) and you can do such things.

I used to work in a company that did something similar. It would escalate issues and if the automation was coded for it, you could respond on your phone and it would take actions against your systems.

One time, someone used this system to call a local restaurant to place an order for pick up.

This is tech from like 15 years ago, if not earlier and it is open source.

All you really need is a phone exchange or VOIP provider who can hide your true identity (this is also how all those scam calls from across the pacific get made).