If you have evidence with dimensions it is wrong, just remove it yourself and give it back.
One possible course of action would be to remove the fence and make her try to sue me for removing it..... she wouldn't win and the onus would be on her. The only issue is there are concrete posts set in the ground and a resin bound drive right up to the gravel boards on her side.... so it won't be a quick easy removal and will require her driveway to be reduced in width first. Bit of a nightmare for her..... but then again, its been a nightmare for me not to able to replace the fascias and soffits on my gable end. The scaffolding at the front and back has now gone and I've had to leave the old stuff in place when the front, back and other gable have all been replaced. It looks a mess cos its crap and old when the other three sides are brand new.