WooCommerce Store Credit:
When it comes to using an appropriate marketing strategy for your online store, there have been discussions of many strategies. It is just an experiment that will teach you the best way to market your online store. We have used many of the strategies and the best one that worked for us the sticky bar on our homepage.
We also used Store Credits for one month and noticed that it works well. You send your customers a gift voucher with store credits which they then can use for their future purchases. You send a 10$ store credit, they will be able to purchase any item worth $10 or below and the remaining credit stays as it is. If they do purchase a more expensive product and use store credit, they will have to pay the remaining amount.
You can directly send them store credits from WooCommerce back-end, using this extension.