Don't want to send back everything? Use Partial Refunds.
SamCart allows you to issue Partial Refunds on any charge right inside of your account.
You can issue Partial Refunds for both one-time charges and subscriptions. This feature works with charges made through Stripe, PayPal, Authorize, or any other payment processor.
Issue a Partial Refund
To issue a Partial Refund, open any order. You can open an order by going to the Orders tab on your left-hand navigation bar, and then clicking on the order ID for the order you want to issue a partial refund for. This will take you to the order's full order page.
Once you are on the order page, scroll down to the Order Summary section of the page and click the Refund button next to the product in the order that you would like to give a partial refund for.
This will open a popup window where you can choose to fully refund this line item, or issue a partial refund. Select partial refund, and enter the amount you would like to refund to your customer.
If you enter a number higher than what your customer paid, you will see an error message. SamCart will not let you refund your customer more money than they paid you. So don't sweat that!
After you enter your amount, click Refund. Once you click the Refund button the partial refund will be issued, and you're all set! The status of the order will now be Partially Refunded, and Total will reflect the amount collected from the order after the partial refund. 
Important note: PayPal refunds can only be issued within 180 days of the purchase.
SamCart Keeps Reporting In Order
After you issue a partial refund, the order will be labeled Partially Refunded. All of your reports will be updated so you can always quickly identify exactly which orders have received a partial refund and trust that your stats are always up to date!