The refund process can be done from your STC Pay wallet, not from the PayTabs Dashboard

Note : 

The Merchant will maintain a fair policy with regard to the return/cancellation of merchandise or services and adjustment of Transactions. The Merchant will disclose its return/cancellation policy to Customers. If the Merchant allows a price adjustment, return of Products or cancellation of Products in connection with a Transaction from a Customer, the Merchant will initiate and authorize a Refund Transaction as soon as possible following receipt of the Customer’s request for such refund/adjustment by using the refund function of the Service. The amount of the refund/adjustment cannot exceed the amount shown as the total on the original Transaction. The Merchant is not allowed to accept cash or any other payment or consideration from a Customer in return for preparing a refund to Customer nor to give cash refunds to a Customer in connection with a Product paid for with a Transaction.