Interesting.
In our area in Issan there is one nice guy that does practically every air conditioner installation for miles (kilometers). Hotels, Tesco's, residential, etc.
There so cheap. 400 baht for cleaning.
Mitsubishi has come out when we had a problem with one of our systems. It was under warranty so it was free. Turned out a snake had crawled into it somehow, weird.
Mitsubishi Heavy or Mitsubishi have great products and service in my opinion.