Disgunted customer

We recently visited the garage in unit 9 Chatsworth and we had filled pressure in our tyres, the guy whom filled the pressure had done our car and then went on to the car next to us, my husband was in the garage store, purchasing some stuff, when he had come back to leave the garage my husband reversed to come out of the place where we filled the pressure, we heard a noise, as if there was something breaking as we reversed, and when the guy who was filling the pressure came running, he stated it was nothing and we should carry on, we then drove off, when we had gotten out of the vehicle we saw our bumpper was cracked, we went back to speak to the manager, who told us he would address it with the owner of the unit 9 garage uthesh, we had gone back the next few days and the manager stated he never got a chance to speak to him, so my husband went inside and spoke to him directly, the owners response to my husband was that he is not responsible for anything that happens in the garage and the pressure place is not a parking bay, we requested footage to show the length of time we where parked and to show how the damage occurred, but they had told us that there is no cameras in the pressure filling side, pathetic service and a pathetic response from owner, not we are sitting with a broken bumpper because of the negligence of they staff...