First, try restarting both your device and the REALITY app, which may update the Coin screen.
You may also try resending your receipt from the purchase screen, which may also update the Coin screen.
If you have multiple accounts, please try logging into one of them to check if your purchased coins are displaying there.
Note: Due to connection status etc., it may take time for the data to be reflected in your account. Please contact us via the in-app contact form if the data is not reflected in your account after 2 to 3 days.