I dont know if different council authorities have their own rules, but around here they are usually spraying the road within half an hour of a reported spill. They use some kind of detergent to break it up, it's about as slippery as the diesel!
But at least there's a 'slippery road' sign put up for a while.
I have reported them to the police a few times and they usually they get right onto it. Rather than calling 999 go to a station near the spill, if you can do.
Re: claims. As above, unless you know the culprit - forget it. The only way you might, i stress might, get somewhere is if the spill had already been reported earlier in the day and no action had been taken - that's negligence on the councils part. Difficult to prove of course.