Son injured in play area

We visited the store on Saturday night, my son went to the play area. we had just received our drinks when my decided to come inside. He ran into an unmarked glass door leading into the play area. He hit the door so hard he passed out and fell off 3 steps that lead to the door, he bumped mthe back of his head on the concrete. The play area is suited to children, the floor is plain concrete and the door has no markings on it. We were told by other customers that a week before another child had ran into the same door, why hadnt they done something about it then. My son had a cut lip from his teeth piercing his lip, a lump close to his right temple and a bump at the back of his head. He could have ran through the glass, broken his neck from the fall or split his head open. the children are at risk. ontop of that there was no child minder to look after the children to make sure they are safe.