A guilt spell might work.
Unless you want a spell related to Vodou specifically, that is.
I know nothing about Vodou myself, so if that is what you're looking for, I can't help you there.
My personal favorite is to charge an opal and hide it somewhere in their belongings or bury on their property. If small it is not hard to hide.
You can also take a picture of them and stick it in a double sided mirror compact and tape shut, visualizing their energy bouncing off the mirrors and back at them ;)