Virgin Media Car Blocking our Drive when picking up child from School

Hi, 

We frequently have one of your 'Field Sales Advisors' blocking our drive to drop off and pick up his child from a nearby school. We have asked him not to park here and block our drive, which he stops for a week or two, but then starts again. 

I can supply photos, reg number and his name from cards in the window. 

Who is the best person to speak to about this? 

Thanks