Yea, they tend to deflect. Then you send email quoting laws and inform them that next email will be trough lawyers, and they pay out quick (personal experience)
So in my case the next step is to find lawyer.
The only alternative to court is Consumer Disputes Board but their resolutions are just recommendations & Finnair has a long history of ignoring them so spending 2-3 years there seems like waste of time.
I generally go direct to the airline these days but if I get pushback beyond what I’m willing to deal with myself, I’ll use one of those services.
[1] Probably the majority of businesses does. But shady used car dealers etc. and Finnair don't.