How should I deal with this harment?

Do you know which school they go to? If so, then you should give that school a call and let them know what's going on. Also, perhaps taking another way home might be something to think about. Catholic schools can be very strict, and I imagine those "kids" can get into serious trouble for what they do. If they are throwing objects and verbally abusing you, then perhaps talking to the police is something to look at (throwing objects can be considered "ault," I believe?) But definitely let their school know. I hope things work out.