You taped the »Return»-Button and entered into cancel-mode. Now each item you add to that transaction will be treated as a negative sale or cancellation. Normally, when closing this transaction using any payment method, Cashy-POS will return to normal registering mode.

If for any reason you want to quit cancel-mode, just tap once onto the red title saying »Cancel mode» on top of the transaction-screen (top left of main screen). The title will disappear and you are back to normal registering mode