Were these children of QR? I think you should write to the children's parents for compensation, they are the ones at 100% fault here.

I have had my fair share of crazy episodes with kids on planes, some of it was so insane I even filmed portions and may share once I figure out how to blur faces in videos.

I was on a Thai Airways A380 in F and it was literally a 3-ring circus going on as kids took turns jumping from the top of one chair to the chair behind it. The father couldn't have cared less.

Or, my experience on Emirates where a 3-year old kid wouldn't stop screaming, so the mom let him roam the aisles unattended so she could continue watching her movie without the screams. The kid had some sort of toy that he eagerly started hitting sleeping passengers in the head with. The mother saw this and would simply shout at him to stop, but he didn't and the mom just went back to her movie and let the kid do what he wanted.

In either instance I wasn't blaming the airline, the fault is squarely pointed at the parents and they should be held accountable for being the legal guardians of their offspring and responsible for their children's actions.