Short story.
Had vacant block next to us for years crappy chain wire fence my big dog never got out.
House built and new owners move in with 3 small dogs, these dogs antagonise my dog for weeks and eventually the fence fails he gets 1 of the small dogs.
I approach neighbours and we discuss fence, it is agreed verbally that a better fence is needed or my dog will be having snacks.
I offer to build it as neither of us have alot of cash. I build 75mtrs of colour bond and place a concrete strip under each section to prevent small dogs sticking noses under.
I get all materials and even collect it all to avoid delivery i mix all the concrete by hand and install with ZERO help from neighbours.
After install thier kids kick balls against it

So after 3 times speaking with the and the last time they told my wife we will pay the $1200.00 after tax time> I go over there today to inquire as to the payment and get this THEY ABUSE ME.. apparently they are sick to death of hearing about this fence and claim that be cause I did not get 3 written quotes and a written agreement that now they won't pay.
So I have poiletly told them to drop dead and have now removed the colour bond fence WHICH I PAID FOR .. My dog is locked in his back pen, they yelled out that they will let their dogs into my yard and when my dog eats theirs that my dog will be put down.....
SO my question
If I paid for the fence in FULL after they moved in am I legally entitled to pull it down given I own it.
I am going to now submit a form for works with a quote I am told in excess of $4500 for the 75 mtrs with concrete strip. Then they will have to pay... 1/2 of the higher amount.
I know I know should have gone the paperwork route in first place, but you try do the neighbourly thing.
Jet