Send your note to this guy:
Matt Weinert - North American Coordinator, RAT
Matt.Weinert@triumphmotorcycles.com
and copy
dealerdevelopment@triumphmotorcycles.com

Not that Matt would/could/will do anything.

Both email addresses come from the website. The dealer development says:
"We at Triumph Motorcycles (America) Ltd are dedicated to developing a lean but focused network of dealers throughout North America capable of offering excellent customer service to both existing Triumph Owners and potential consumers interested in our legendary brand."

Having said that, I wouldn't hold my breath waiting for corporate to yank the leash on weak dealers. But it could be like many large companies, the boss knows what he wants to happen, but unless someone tells him it ain't happening, he thinks everything is working as planned.