Before changing the narration, optative sentences are first converted to assertive sentences.
He said to the shopkeeper, "You are a fool, You have done the opposite of what I desired you to do. Instead of changing the perfume you have changed the shaving cream."

Explanation

He reprimanded the shopkeeper saying that he was a fool because he had done the opposite of what he had desired him to do. He informed him that instead of changing the perfume he had changed the shaving cream.