Reported dangerous drving - Imperial non response

I phoned the company on Monday and was told a Francois would be calling me. Nothing so far. Posted on FB yesterday and still nothing. Reported about their unit 618 driving aggressively on Saturday night. Flashing his lights at me because I was in the way? Wasn't and then overtook 4/5 vehicles using the yellow lane. Did it again after the next set of lights. Imperial certainly don't seem to take this very seriously. All the details have been supp****. You would think with our road safety record this would matter and from a commercial point of view an accident must be a very expensive cost to the company. The mind boggles at the lack of response!