Several times. He seems to think it's fun to torment neighbors
My wife had an issue like that once. She would go for a walk early in the morning and she would take Simba the Husky with her.
Some dumb gringo seemed to think it was cool to leave his big dog free to roam and it went for Simba.
Long story short ( you can look it up here on dr1 for the longer version ), I told her to take " my" rottie for walkies the next day.
Rex whipped the other dog's ass, and magically, no more problems from that day onwards.
So, perhaps that could be one solution, but then again pits are dangerous. Btw I love dogs, hate pits....nasty fukcers.
Another solution is to scare off the dogs every time they are near your house.
An old pot/pan and a metal spoon, make lots of noise, comes to mind.
You could also try your local fiscaleria. I say it's worth a try, in my campo they have been responsive the one or two times I went to complain.
And most importantly, stay safe, and keep your dogs safe.
I would hate to be in your position and would probably carry a firearm ( in the case that you have a license ), or at the very least a machete.