If you want to return a part of your order, we will issue a new Credit Voucher, or a refund to your Shukran Pay wallet. The rest of the amount will be refunded to your Credit or Debit Card.

This could work in the below manner: 
Imagine an order with three products worth OMR 20 each, having a total value of OMR 60. The order was paid for with a Credit Voucher or Shukrans worth OMR 30 as well a Credit or Debit Card. If you return two products, your refund of OMR 40 will be split between a Credit Voucher or Shukran Pay, worth OMR 20 (refund of OMR 10 for each product) and a Credit or Debit Card refund worth OMR 20 (refund of OMR 10 for each product).