Revising A Builder Invoice - Am I being Unreasonable

[IN51GHT]

sone said:

Compromise is the answer! A quick phone call, both parties bleed a little. I'm sure there is middle ground somewhere.
I couldn't have this hanging over me especially at this time of year.
It would seem both client and contractor are at fault to some degree.

Which is the route I am trying, but SWMBO is now refusing to compromise as "it's the principle"

Happy fking Christmas.