When your business receives a card dispute (also called a chargeback), the cardholder's card issuer pulls the amount for the dispute from Stripe (who your platform partners with to process your payments), as well as that network's dispute fees. Stripe passes these on to you, the merchant, and debits your platforms balance for the dispute amount plus network dispute fee.
If you issue a full refund on a charge before a dispute happens, it is no longer possible for the cardholder to dispute it. So you are protected from any future dispute or dispute fee.
Once a cardholder initiates a dispute, it is no longer possible to avoid the fee.
All disputed payments (also known as chargebacks) incur a $15.00 fee (or local equivalent).