While they may appear to be the same thing, there are some significant differences between a credit card chargeback and a refund. Although the customer receives their money in both cases, as the merchant, you will incur additional fees as a result of a chargeback.
Chargebacks are also monitored by the payment processor. If a merchant's chargeback ratio exceeds a certain threshold, which is typically 1%, it can result in serious consequences such as higher fees, larger reserve requirements, fines, or even account termination.