Having said that I don't think the whole hour should be spent fucking.
That largely depends on what you mean by fucking for the whole hour? That can take many forms.
Besides, a decent working girl will establish the parameters of what she's happy with before money changes hands, either on her profile or in person. I also think it's up to the punter to check exactly what he's paying for beforehand. Don't assume anything!
I don't think a punter can complain about a 'come once or twice' service if that's clearly established beforehand. I personally wouldn't book a girl who stated that, however.
It's those girls who try to change the rules after money has past hands that used to piss me off in the past.
Now, I always have a plan B or C, so I'm quite happy to walk away if such a senario occurs.