Unsecured automatic on the Kia Ceed 1.4 T-GDI DCT ?

Today, my Kia Ceed automatic, parked in the supermarket parking lot, rolled backwards from the parking space into another standing vehicle about 8m away. I didn’t notice it until I returned to the parking lot and found the police and a injured person there. As it turned out, I had forgotten to put the gearbox on P in the hurry. Unfortunately, I didn’t wear the handbrake either. When I re-educated the situation, I had to find out with horror that sic h the key was pulled off to D. There was no warning signal or similar. The fact that the car then simply rolled away in D-position even with minimally exhausting ground, puts the crown on the whole. Here I wanted to ask completely astonished and terrified here if this is normal and right with Kia. With my previous vehicles it was simply impossible to leave the car like this. Now I have an annoying damage and am totally operated. be. Or ?