Open your main settings and tap your Apple ID avatar. Click the `Media & Purchase` option and scroll down to locate the `Purchase History` section in order to display your purchase history and select the purchase which wasn’t received. 

On a computer with iTunes installed, click on ‘account email’ in the iTunes Store to access your account; you will be prompted to insert your Apple ID and password. Click 'Purchase History' to display your purchase history and select the purchase which wasn’t received.