[annabella]

from experience....
Changing his phone number may not help- I completely understand the dynamic of the neighborhood (friends showing up unannounced, leaving door unlocked, etc). But think- he would have to get his new number to all his friends. It's bound to work its way around to her, or she may be able to get it from a phone left unattended while at another friend's house, etc.

If the phone he has doesn't have a feature allowing you to block the number, I urge you to have him contact his service provider and see what they are willing to do (on this note, Sprint may be ridiculously difficult and unwilling to do this- when I attempted to block a number after an unsuccessful number change, I ended up having to provide them with a copy of a police report that had been filed).