LMG pre-owned aren't interested in selling cars

I contacted LMG pre-owned to enquire about a mercedes-benz they were selling that I was very interested in. I made contact by sending them a message via Autotrader.co.za and a sales person phoned me the same day. He confirmed the car is available and asked if I had a trade in, I told him I might trade in my Kia Koup and his attitude immediately changed. For some reason he said he would send me pictures and phone me back. I never heard from him again. What I didn't tell him was that I planned to pay cash for the Mercedes and I might privately sell the Kia if the trade in amount was too low. I feel like he judged me based on the fact that the Kia is not a "luxury car" and immediately lost interest in me thinking I couldn't afford the Mercedes. He also had a very brash demeanor over the phone and did not talk to me in a professional manner. I would recommend you think twice before buying a vehicle from this establishment