how do i get a refund for an app

A few days ago I was looking at my rosetta stone app and an offer to purchase an app that I already owned appeared. Out of habit I placed my thumb on the home key to clear it but instead was giving the phone approval to purchase it. It was for $212.49. I already own this language app and don't need to spend another $212.49 for the same app. Can I get a refund for this purchase?