Anyone know of a friendly telephone wiring tech in Wellington?

I have friends residing in a two-storey house where they have recently had fibre installed (Chorus) and VOiP.  Due to various telephone handset configurations, they want to retain the internal wiring loop for this.

I tested their wall jacks (router to wall jack etc), and they appear to be dead.  I can only think that when Chorus cut the outside pole-to-house copper, they may have also severed the internal link in/on the house.

They would like a technician to ascertain if the internal circuit could be restored.