Just started using Zoho for our sales team, however we are not yet using it for transactions (that happens in another system.) Currently, in Zoho, we are only tracking sales person's revenue by Closed Deals.

Our products come with a 30-day refund period and, if a customer refunds within 30 days, we deduct it from the sales person's total sales for that month (usually the month after the deal was actually sold.)

What is the best way to adjust the sales person's revenue in NetSuite without throwing off other numbers in the system?