You can create a bank deposit to raise or record a credit from your supplier for an expense.
Here's how:
Click the + New button and then choose Bank Deposit.
Scroll-down to the Add funds to this deposit section:
Enter the amount refunded by the supplier and choose the Category/Account that you selected on the initial expense or cheque.
If this refund was for an expense that you linked to a customer or project, select the Track returns for customer checkbox, then select the customer or project. That way, your costs will not be overstated.
If you deposited customer payments for invoices into the bank account along with the supplier refund, add them in the Select the payments included in this deposit section.