I didn't know this was a thing until someone mentioned it today on Facebook but Chorus will courier a replacement ONT cable for one that's missing or damaged for free.
It may not help now, but definitely something to remember next you move house.
My father bought one a while back when a tenant moved out and took the cable with them.
Very cool, places like JayCar and PBTech sell them for $40-50 each.
Wouldn't you just call them if you needed this anyway?
Or is this just to speed up the process?