In my experience, these "commands" are also quite vague. Instead of expecting the "help", they should just put (x) and show the menu where I can click on things and be done with it.

On voice interface, your best chanse is to connect to an actual intelligent being as soon as possible because getting the options is a frustration by it's own.

My experience is that they tend to repeat their intro dialogue, which is often something like "tell me a few words about why you're calling, for instance you could say 'upgrade account' or 'billing issue'". Unlike keypress phone trees, they virtually never enumerate all the options.

If I'm saying 'help' it means I've tried that and failed, so it's not clear what the benefit is.