Mirrors are very powerful for returning energy back to someone, and are perfect for revenge spells like this. You'll need a few supplies:

A small mirror

Black permanent marker

Long piece of black ribbon

Whole bay leaf

Burnt wood ash

If you can, cast this spell on a Saturday night. First write the person's name on the face of the mirror is big letters, then set the bay leaf over the name. Wrap the mirror and leaf in ribbon a few times, then add a generous pinch of ash over the leaf. Wrap a few more times and then tie with a solid knot.

Place one hand on either side of the mirror, and say:

From me to you,
Comes back times two.

Keep the wrapped up mirror charm under your bed, until you feel that your revenge has taken place. Don't leave it forever though. Once some bad luck has fallen on your adversary, remove it and dismantle the spell.