Lehrer Fireplace & Patio

Apparently the only person who can answer a question is the owner, and you have to wait 3 weeks for that!
I wanted to convert my 30 year old existing wood burning fireplace to a gas insert. I had a concern about the orignal firebox. I have the name and model of my existing firebox. After trying to explain my situation and even showing them pictures they still had no clue about what I was talking about but, they were still willing to sell me an insert. I asked if it would be possible to speak to an installer. I was told no, they work out of a different location. I asked if someone could call me, they said no but, I could have the owner come out for a free estimate… In 3 weeks. I thanked them and left.
I then called the another location and that salesman was worse. I explained things again and he abruptly said «I have no clue, I’m in sales not an installer.»
They are happy to sell me a $ 5,000+ fireplace insert but are unwilling to help answer my questions. What burns me (pun intended) is the type of fireplace I have is extremely common in my community and I’m certain they have run into these in past. All I want, is to find out up-​front if this is a problem or not and how much more it might cost for installation.
I for one wil be taking my current and future business elsewhere.