Pleased to have you here, @somani_vivek.

To zero out your customer's balance and Accounts Receivables, let's create an expense transaction here's how:

1. Click the Plus Icon (+).
2. Go to Expense.
3. Choose the name of the customer.
4. Select the same bank account used in processing the refund.
5. In the Category Details section, choose Accounts Receivables in the Category column.
6. Enter the complete expense details.
7. Click Save and Close. 

That should do it! For additional insights about processing customer's refund, you may check out these articles:

• Record a customer refund
• How to refund a deposit and close an invoice

Please don't hesitate to visit us here in the Community if you have other questions about clearing out your customer's balance. I'm always here to help.