Your situation is not funny, but it reminded me of an old story from the internet in the 1990's, The Neiman Marcus Cookie Recipe
> My daughter & I had just finished a salad at Neiman-Marcus Cafe in Dallas & decided to have a small dessert. Because our family are such cookie lovers, we decided to try the "Neiman-Marcus Cookie". It was so excellent that I asked if they would give me the recipe and they said with a small frown, "I'm afraid not." Well, I said, would you let me buy the recipe? With a cute smile, she said, "Yes." I asked how much, and she responded, "Two fifty." I said with approval, just add it to my tab.
It ends with them being charged $250 not $2.50 and the author shares the recipe with the world as revenge.