Bully

I purchased a car for my son. The car company neglected to inform me that it had had several modifications. They admit this. I cannot insure the car for my son to drive. Thus making the car not fit for purpose in which it was intended.
Black horse could not care less, their argument is I should have known. If the car showroom do not know, how am I supposed to.
We went around in circles for about 30 mins. He told me their answer was no, regardless of if I logged a complaint.
He was getting louder and more aggressive in tone as the call went on. Eventually I told him not only did I want to log a complaint, I also would be contacting trading standards and the financial ombudsman. At this point he yelled that I had contradicted myself throughout the call, was lying and was committing perjury!! I believe he said this to frighten me into shutting up and not escalating the complaint. Silly man.
I hung up imeadiately and called back to log another complaint about him.
I have now contacted the financial ombudsman to complain about my initial complaint and my treatment by this bully.
I would like to say my experience is a one off.
Alas the reviews make it clear it's not.