Making claims without evidence

Duram is a leader in roof paints. They claim their Cooltech paint reduces heat in the house by reflecting light. However when I ask for data on what the expected temperature difference is at the bottom of a steel roof structure, they can't answer me. I have done the experiment myself coating a dark green roof with silver reflective paint and I measure a reduction from 54deg to 42deg. A simple experiment to do. I shared this with Duram.

Is it reasonable for a prominent roof paint supplier to NOT have such data? My opinion: it is not. Claims must be substantiated with data and measurements. I even suggested to them I will do the experiment on their behalf but I got no response.

Are customers in SA reasonably protected from manufacturers making claims without substantial data or evidence? Obviously, we are not.