Give the radio station a call and inform them of the false advertising, ask for a copy of the ad, offer to pay for it as you need to give it to the relevant authorities who are pursuing the false advertising claim.
In other words, where-ever this guy goes his cage be rattling, with some luck he might piss off from the island.
Also, approach a journalist from a local paper etc and ask for an article to be done on malpractice pruning, warn the home-owners of the shoddy work.
I have a stack of successful outcomes against shonks, all you have to do is be honest and truthful and play by the rules.
