I'm just back, and I did and I did (read about the issues and then ride).
I found and used a local company
http://www.pandatourchiangmai.com/# Panda Tours who operate and use their own facilities, for the elephant training and trekking. The whole thing is integrated with the local villages, and you at least feel you are putting something back. I have no reason to suspect that the text on the front page is anything other than genuine, it fits everything we saw and heard.