We know you've got options: blackmail, extortion, calling a guy who knows a guy.
But before you do anything rash, allow us to suggest something a little more...legal: dead flowers.
Introducing Dirty Rotten Flowers, your new source for revenge in floral form, now accepting orders just in time for Valentine's Day.
Yes, you read that right: you now have a simple way to deliver dead flowers directly to your archenemy. If your dispute is of a business nature, we recommend trying the Dirty Rotten Flowers namesake bouquet—a classic collection of decomposing flowers, collected from LA-area florists. (You can ask them to include a card, in case it's personal—for example, "All the best, Jay. Love, Conan.")
But if your beef is of a more romantic nature, go for the Morticia—it's a collection of a dozen roses with a twist: the tops are lopped off. Whichever you choose (and we won't dissuade you from getting both), your foil will receive them wrapped inside an elegant black box—basically a casket for flowers. Oh, and for some reason they also offer live roses, but those are only available in LA for now.
You didn't want those anyway.