However, I can see this working quite well for help desk services if the paradigm is flipped. That is if I end up speaking with my electronic assistant who then appears to negotiate on my behalf with the company. As apposed to me calling an unknown entity. It may in reality be the companies service, or even infrastructure that my electronic assistant is running in, but the impression to me would be I'm speaking to my already familiar electronic assistant.
The benefits of this are many, and only possible with something like Duplex. In addition to familiarity, technical support can be delivered at the right customer knowledge level skipping past insulting time wasting support like "is it plugged in?". Also a "continuity of care" model can be adopted by companies to provide a continuation of the relationship in the context of prior interactions. The list goes on.
This might in fact be the one service that is a bad enough experience, that I would gladly welcome our new robotic overlords.