I'm worry about the refund process on Apple. As I understood, if a customer ask Apple for refund and Apple accept its, the owner of the application is not notified, instead, the owner shall be monitoring the receipt data with Apple to look for the Cancellation Date field in the receipt.
Apples says... "If the field has a date in it, regardless of the subscription’s expiration date, the purchase has been canceled—treat a canceled receipt the same as if no purchase had ever been made" (This is the recommended process)
Now, I'm wondering if it is possible to detect manually a refund from iTunes Connect and obtain the receipt data of the product canceled? I have to say that I don't have access to the Payments and Financial Reports section to check if this is possible, that the reason I'm asking.
Not sure what your goal is, i.e. it is definitely not possible to get information on the customer who got the app refunded.
Here's a way to get more information on the refunds:
Go to > Sales & Trends
Filter by "Transaction Type" and you get an overview of all your refunds (possible to filter by app, via Content "App Name")
You don't have any ways to track refunds explicitly via "App Analytics" (only shows the totals, i.e. downloads/purchases minus refunds) or "Payments and Financial Reports". For the latter, it's the same, they only show you the totals.