Bird spikes

My neighbour has attached Bird spikes to the top of my fence ( I put the fence up 6 years ago cost £1700) I needed a fence to contain my dog.
Can they actually do this ? No one has asked my permission. It's on the fence right next to my bird feeders as well.
I only discovered this today. I am furious.
What can I do to legally remove it.
The neighbour is aggressive