Revenge spells have the problem that unless your slate is clean, they can and often do backfire. I cast a curse/spell on a less than savory landlord once and I ended up evicted that week because his fianc? wanted her room back. It was a complete and utter mess that could have been handled differently.
Spells work best when you have a clear head...and magic travels the path of least resistance. Also ask yourself - would you want someone doing the same thing to you?