Date of purchase is not confirmed

Hi, you can kindly confirm your purchase through his process ;

1. Open the Settings app.
2. Tap your name, then tap Media & Purchases. 
3. Tap View Account. You might be asked to sign in.
4. Tap Purchase History.

View your purchase history for the App Store, iTunes Store, and other Apple media services - Apple Support

OR you can also try this

1. Go to reportaproblem.apple.com.
2. Sign in with your Apple ID and password.
3. A list of your recent purchases appears. If you’re not sure what you were charged for but you know the amount of the charge, search for the amount. If you're looking for information about older purchases, find your purchase history in Settings or Account Settings on your devView your purchase history for the App Store, iTunes Store, and other Apple media services - Apple Supportice.

you can also visit the apple support site for more information

Official Apple Support