We have a discount running for 10% off if you spend over £250, a customer has placed 3 orders that total up to over £250 and he has requested the 10% discount. It seems that there is no way to retroactively apply the discount and as the customer has paid via PayPal Express checkout, if we were to create a new order and refund the original order through Shopify, that the PayPal payment would automatically be refunded by Shopify. Is there a way to prevent Shopify refunding the PayPal payment? Otherwise it means sending the customer a new PayPal request which is a bit of a pain.
You do not have to give the full refund, You can select the order, I have a screenshot below. Go in order details and select refund on the right top. Once you select refund it will give you an option on the right, you can select the amount you want to refund and click ok. this will automatically give customer a refund.
All the best.
Let me know if you want help.