Let Magento 2 store credit extension solve your problem. With the help of this extension, store owners can refund customer purchases by store credit, then the customers can use store credits to buy new products, get discounts for new purchases, pay for taxes or shipping costs, etc. This would help the refund process no longer is a complex and annoying process. Moreover, you can also award store credits for your customers for their actions in your online shops and allow them to use the store credits in following purchases.