You rushed in to it and didn't check it properly. Very different to be scammed.
You agreed to buy the car without seeing it and paid using a method where there was no comeback whatsoever.
Classic case of always somebody elses fault.
Not only that but apparently there is an abundance of amazingly safe £1500 vehicles on the market.
Instead of picking one locally which would be easier to inspect, pick up and resolve any issues. He decided to pick one 5 hours away.
I'm sure something isn't adding up.
I once sold a fully working electrical item when there was knee deep snow outside, the deepest snow I've ever seen in my life, even aldi was shut and I had to walk to asda and back as no car could get through. I told the guy that it wasn't a good idea to pick up and wait for it to clear some more as the roads had only just been gritted but my driveway was still knee deep.. I wouldn't be able to help him carry it until the snow cleared. I didn’t want me to fall or drop it and then be left with a damaged item. He wanted it straight away and brought a friend. They proceeded to drag it through the snow to the car. I showed him that all the electrics were now covered in snow and it wasn't just a little bit they had literally scooped up a pile of it inside whilst dragging through the snow. Like a shovel.
He text me 2 hours later to say he wanted his money back. I explained that wasn't my fault his negligence broke it and he said he dried it before turning it on.
I explained that kind of thing would take several days in a high temperature environment to be completely dry. Not a simple wipe with a cloth.
Again his fault for not knowing how water and electrical components work.
Some people will always learn the hard way.
OP is angry at the seller but in reality he is the one to blame for this whole mess. He put his own kids at risk.
I once had a cheap Chinese power adapter blow up on me. Luckily no fire. But I swore to never buy anything like that again. Could have wiped out everyone in the house.
Buy cheap buy twice.