I have now had a reply from the airline who have decided it’s all the fault of the airport not their staff.
The rest of the reply is the usual,
“we are sorry to hear, hope you will fly with us again boilerplate” that I assume is the same format they send to everyone but a single sentence in the email says,
“We have escalated this to the airport authorities”
This reeks of passing the buck in my view as clearly the responsibility is the airline and its staff to ensure the appropriate people are sitting in the exit row seats.