I have no idea how to proceed in your case with your airline. When I see children in the emergency aisle, I call the flight attendant immediately. However, the airlines I normally fly are well aware of the rules and will not allow a child to stay in those seats, so a polite request to move the child is all that is needed. This has only happened to me, when some wandering brat sees the empty middle seat in the emergency row and thinks that's going to be a cool place to sit. Not gonna happen on my watch. I'm not familiar with your airline but since this is a safety issue, and the crew does not appear to care much about safety, I think your best response is to avoid flying this airline again. Why would you want any compensation on an unsafe airline? Children, broken necks, etc. can't be sitting in emergency rows, period. It is a completely unneeded risk. If the crew thinks safety is "too much trouble," you don't wanna be on that plane! I admit, if I'd encountered such a circumstance in the U.S. and the airline did not acknowledge that the problem needed fixing, I would probably feel obligated to drop a note to the FAA. I would not be seeking compensation, I would be seeking some assurance that this would not be happening again.