Sand SHifters Sand Blast all fellow highway users

The company called "Sand Shifters" have a fleet of yellow coloured trucks with red writing on that transport sand all over. I travel the R21 between East Rand and Centurion daily and every single time I see one of their trucks, not once is the back of the truck covered, as is required by law. What his means is that mine and every other car passing their trucks literally gets sand-blasted as long as you are anywhere near their trucks. Obviously this damages the paint work of every car around these vehicles. The fact that Sand Shifters as a business see fit to ignore the law and mess up fellow citizens cars is a an absolute disgrace! Obviously the owner of the business does not train or enforce this with his drivers. This is a serious indictment on the owner of such a poorly run company!