Sorry to hear of your experience with carswithnoreservereading.
I have no issue with the fact that they sold a car with issues, they will never have garage queens for sale.
But what is disturbing, and which is completely unacceptable, is to have undertaken work at their expense and by agreement which left the car as a clear MOT failure.
If they are accepting the return and letting you walk away, that is something but I feel they are lucky if you don't report them to trading standards.
They may not be a dealer in the conventional sense, but they should not be removing safety items from a car.