I am about to lose my mind with my neighbors across the street and the feral cats that they are housing/feeding!!!!!!!

These cats are poo pooing ALL Over my lawn front and back.. it smells disgusting as you walk up my driveway and I have a 14 month old who I want to be able to let play outside in the summer without worrying she is going to step in /touch etc cat poop. I dont know how to get rid of these cats!!!!
Its disgusting and filty and a health hazard!

1) does anyone know any agencys etc that will help me do something about this problem- permamently?

2) does anyone have any proven suggestions for keeping the cats away from my house?

ETA: Im in the town of North Hempstead and they have already "caught and released' the cats and supposedly neutered them.. which was not effective since the cats have continued to breed!!!!