Use a black candle, with a picture of the person (if obtainable) placed underneath, also a piece of parchment with the person’s name on it.
Carve the Divine Names “Eel kanno taf” onto the black candle.
Anoint the candle with Banishing Oil. Burn for nine nights, each night reading Psalm 94. Put the candle out after Psalm is done (NOT by blowing it out). On the last night let the candle burn all the way down.
While the candle burns (on each night), meditate and focus STRONGLY on the aim in mind. Imagine STRONGLY the person leaving you alone; imagine STRONGLY their evil deeds turning back onto themselves. Do this for about 5 minutes each night before you pray the Psalm.
(Note: a purple candle could also work for this, but I used black because this person had been REALLY harassing in a serious way).