How do I deal with a neighbor who harms my mother by vandalizing household utilities and verbally abuses my sister?

Abuses from a neighbor are to be dealt with by first offering advice and admonition, then by enjoining good and forbidding evil, then by seeking assistance from neighbors, relatives, and respected members of the community. If this does not succeed, then recourse should be made to the ruler and the competent authorities. If none of these solutions prove effective, then moving to another suitable residence is the last resort to seek safety and avert harm.