Hi there @Edna3!
Don here from Shopify.
If you'd like to check which of your orders pertains to that return/refund you saw go through there you can head to your Orders menu in your Shopify admin.
There, you can filter for orders where the payment status is refunded so you can see which orders processed in your store have been refunded.
Check to see which entries here would relate to the figure you see in your reporting (it may be one large order or more than one order combined) so you can see where this was originally taken in and when and where it was refunded.
All the best!