I want certain customers to have a fee when paying with credit card, and other customers to have no fee with this type of payment. I tried entering group settings and changing the fees for a particular group, but it changed the setting for all groups.
Is there a way to modify payment gateway fees based on client group?
You can accomplish this by adding the same gateway twice, configuring the two gateways differently and then making each of the gateways available in each of the groups.