Seeing as you don't have a contact email, I thought this might be the best approach. Not sure if this individual is the owner or a member of staff, but they might want to avoid cold calling / canvassing houses when there are clear signs asking them not to, and signs asking not to leave junk mail.
In response to the company owner, I'm sorry but I find it very hard to believe that someone hired to only hand out leaflets would ring doorbells if they don't officially work for the company as a labourer. There are clear signs about canvassing and junk mail, so why ignore it?