The payment portion of the refund will net against sales under the relevant payment type (e.g. cash deposit, Toast Deposit)
If cash sales were 150 and cash refunds were 100 - the cash deposit booked would be the net 50. The "Refund" mapping is for the sales offset (debit) portion of the accounting. It is the reversal of a sale except that Shogo does not post the reversal at the sales category level.
e.g. A $100 refund will basically post (in isolation) as:
Debit: Refund: 98
Debit Sales Tax: 2
Credit: Toast CC Deposit: 95
Credit: Toast CC Fees: 5