Dodgy new installation

Last Monday, NBN technicians come out to install FTTP to a new build. By Wednesday, the external box is warped, falling off the wall and NBN won't come and fix it unless the service actually stops working. I also think this is the wrong external box to have used (this seems like a box better suited to a weatherboard wall with cable entry from underneath, as it leaves the hole in the brick wall open to the elements, instead of sealed like the smaller style of box would do, and forces both fibre cable to bend out of the hole sharply to enter / exit the base of the box.

I questioned the installer and he said they have to use the old style of box until they are gone. I'm calling BS and incompetence, but the issue is that they have charged me $300 for this sub-standard install, and that is being billed to me by my ISP, so if I don't pay it until I get a satisfactory resolution to the installation, I risk potential issues with not paying the bill - such as denied service, listing on a credit agency etc.

I have little leverage except to actually pull the box off the wall entirely, render the service inoperative and then risk NBN charging me even more to rectify the issue... Would appreciate any thoughts or possible resolutions... NBN don't want to know, they insist I go through the ISP for anything...

Would appreciate thoughts, suggestions or a way to resolve this matter before I pay the new install fee and it slips away as anything important to anyone but me...

Cheers!

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