Neighbors that simply don't care!

I installed a 90' wood fence. Between the neighbors house and mine! They approved. And did pay a small amount.I was so thankful that they did! They have been watering the fence daily for a year now! The water goes up and over into my yard, drenching the fence! Currently the fence is warping! I emailed asking for their help so the excess watering doesn't continue to saturate the fence any further , explaining the fence is getting damaged. Their response" the fence is low grade wood and it will fall down in time. Watering isn't going to matter! Next. My avocado tree that is 70+ year old ,was looking ill. I called out a specialist. The diagnosis was neighbors overgrown tree was actually on top of our tree, going through it, pushing the avocado tree down, and blocking the sunlight. We paid a large sum to remove Their unkept tree off of our tree at the property line. Their trees all along the fence are all insect infested, are full of dead matter! One of their trees actually lays on their home. Before I paid an exorbitant fee to cut back THEIR trees... One of their trees was laying on MY ROOF! Im glad to report....The avocado tree is thriving! Yeah! Now??? Their other tree is growing right by the fence.100% of this hibiscus tree is so overgrown it was touching my house! I had that cut back too! It was covered in bugs!!! They weren't happy with me removing their branches.. But I only did it on the legal property line! I usually wouldn't even give thins my time or stress, but my dogs track all these bugs and leaves in ,that it is just becoming a hassle.