Poor service and response

Bad service I have sent my car for service during the lock down around June 2020 and I always take my car to them since I bought it there. After I took my car to them I've never travel any long distance or do anything to the car. What happened is when I travel to kzn over the weekend I only found out the front bumper does not have nuts on top, it's only tied at the bottom, and it has fallen down and only one nuts was holding it.

That has caused a huge damage to my car and when I phoned to ask them about this, the response from Faizel was that they are not a panel beater but a car dealership. It was a surprised for me because this car is for 2015 and it was a brand new car from them, I do not open my car except the garage when they check oil en water. The second people that are touching my car is them and when they do measure service they do so many things to make sure all is in order but now they don't wanna hear a side of my story the guy was rude and not listening to me, all I wanted is the nuts to be placed back, the impact of this has caused scratches in my car bumper and my wind screen got cracked, am so disappointed.