As a current call center-ish worker (i only deal with internal ppl/employees) I would be fired in a heartbeat if I disconnected a non-abusive call. Even if I disconnect an abusive call I have to tell my supervisor and document the fuck out of everything.
Also if you call into an HR contact center and abuse your HR staff, please do not be surprised if you at minimum get a writeup lol.
I've had maybe two or three unhinged calls in the last 7 years, and as a level 3 I've got a lot of latitude. In each case, I've called my boss immediately afterwards, and followed up with an email. He's next in the firing line from the client. He's backed me each time.