How to reissue coupon to customer while doing return transaction

Hello Community,

We are trying for Coupon promotion to customer's. here we go for scenario

1.Customer came to store purchased item with coupon   $767+ 35% of Coupon + tax 6.23 $ over all price of the product == $504.78

2. Customer Came for returning same item which he/she  bought with coupon.

3. Here how to return that coupon amount to customer ?

Can anyone help us please..

Thanks,

Surendra.