I too would recommend that you use someone who knows what they are doing. We were let down badly by an Aga installer who was to install our Rayburn wood burning stove, with central heating and an oven. This meant we had to find someone local and it was a problem, no-one seemed to want to do it. It took us along time with a lot of frustration to get anywhere near a satisfactory result.
I’m sorry I cannot recommend anyone to you but have you tried to contact the manufacturer to see if they can recommend an installer for you.
Tradesmen who do not respond to enquiries or complaints are a nuisance. If they were to say I am not interested then it gives you the opportunity to find somone else. At least you know where you stand.
Best of luck.