Dangerous car

[Tinaoliver64]

Hi I bought a used car from a dealer, on the way home the car broke down, lifted the bonnet there was no coolant in it, refilled it and carried it broke down twice again same day I bought both times resulting in coolant left in bottle phoned dealer they had it back next day and put a new coolant bottle in as they said the old one was leaking, however the car continued to just switch itself off in traffic and leave me stranded in middle of motorway, it also ran out of coolant again within an hour of driving the car phoned them up again and was told the car wasn’t like that when I bought it and to piss off, consumer rights helped me to write an email to them so I did giving them 14 days to reply in the meantime I had to keep filling up coolant bottle every day, I phoned them they refused to speak to me, I sent them another 2 emails telling them that I would be informing trading standards as the car was dangerous, after 2 other opinions from 2 seperate garages I was told the head gasket was gone and a crack in the engine block, they are not responding to my emails or my phone calls what should I do now it’s been 5 months with my car being sat outside because I can’t afford to get it fixed help