Hit by driver denying involvement

[HappyFrappy]

Yesterday, the car behind ran into us. It was a queue if slow moving traffic, I believe, but don't know, that he was in his phone and just didn't react fast enough.
We both stopped and swapped numbers, and I took a photo of his car (though he had already pulled over by that point).

I called the insurance company on the way home, who were pretty unhelpful as I couldn't tell them exactly what damage there was, and said I should call back (I had wrongly assumed they'd want the car taken to one of their garages to work out what was wrong).

Then today the other driver has got into contact and is v cross we have involved insurers and is now denying anything happened, saying that he never touched the car (in which case, why did he stop and give us his number?!).

Apparently I can't update details of our claim until 9am on Monday morning. What else should I be doing? Other than having a dash cam (which I don't)

Was there damage to his car and yours?

Yes, was there any visible damage?

Report the accident and what the other driver has said to.the police. They won't do anything but it might be handy to have it all on record

I dunno about his car.
Our car has a crack in the bumper, and an imprint of, I suspect the round bolt that attached his numberplate to his car - a small circular dent in the paint work.
But it's drivable, I think just needs a new bumper.

Did you not take photos of his car?

I have a photo of his car stopped on the other side of the road. But I guess he could argue I just randomly took a photo of his car (though how I knew his number in that case...)

If you have damage to the rear of your car and he gave you his details then I think he's going to struggle to wriggle out of it now.

If someone runs into the back of you then it’s basically their fault. Give the details and photos to your insurance company any get them to sort it.

This. He is at fault and likely will have slight damage to his car, as the front of cars do crumple more easily as is intended. I went into a small van in front in queuing traffic once, there was no damage to the van but my front section was dented and I cracked the numberplate.

But no photo of the damage to the front of his car?