I sent a complaint to AC over an access issue at the airport contract station in the US, and they were all "u wanna fight me, bro - see you at the CTA"
They made a million excuses and quite graciously closed with an invitation to file with CTA and DOJ, so I did. CTA sent me a bunch of documents to respond to with a deadline of less than a week, received the day I came home from major surgery. I was not in any shape to involve any of the passenger advocate groups. I somehow got my comments together (basically saying the same thing I had said: what happened) but CTA foreseeably took their side (compliance!)
(I would note that DOJ issued them a direction to do better under the ADA, and none of the airport contract staff were ever seen again, replaced by a different contractor.)
I didn't want compensation. All I wanted was for them to say "what we did was poor service and we will do it better in future". I provided some free "consulting" about a no-cost solution to make my problem go away. I anticipated having to use that service again and again and I did not want a repetition in my future experience. They said everything but that.
They rely on "compliance" rather than doing the right thing.
In response, I do what they told me to do, which creates a lot of extra work for them. If you ever see someone pushing through a departure lounge containing all the passengers of a full widebody awaiting boarding, and displaying a BP to the gate agent and then standing aside right there and boarding before zone 1 - that's me, working to rule.
Lack of customer service just might be policy because, at AC, it's about compliance not service.