1 Thessalonians 5: 15 Make sure that nobody pays back wrong for wrong, but always strive to do what is good for each other and for everyone else.

Galatians 6: 7 Do not be deceived: God cannot be mocked. A man reaps what he sows.

When that person cuts you off, curses you out, speaks negatively of you, breaks your heart, or does anything against you, pray positively for them.  Not a threat type of prayer, but a prayer for their salvation, revelation, and blessings.  For, we sow what we reap, and think of the abundance of blessings can we reap for ourselves by blessing those that persecute us.  So, before we rise to anger, instead we choose to pray and sow a positive seed for ourselves in the process of it.