I got 20,000 for the same problem about twenty years ago and was told it was the standard rate. I would have assumed the passing of the years with associated inflation and enhancements would have raised the level of compensation.

My memory is not the type that remembers what I paid for the flight but I would guess it was way fewer Avios and negligible fees. I think at the time F was x2 the Y Avios (and J x1.5).