Need reccomendations for a zone A/C repair (LG system)

Last summer one of the zones of our LG A/C system stopped working. We had a well known local company come out to assess the issue but after a 3rd visit they stopped the project. They also won’t return my phone calls this year. I’m guessing that they don’t want to continue the project. Can anyone recommend a reliable service that could help us? I’m told that LG systems are hard to find those willing to service them but this may or may not be true.