To add the admin switches you'll need to mess around in the database. Alter this according to your needs. USE AT YOUR OWN RISK. Be sure to backup your database before messing around in there.
Code:
INSERT INTO configuration (configuration_title, configuration_key, configuration_value, configuration_description, configuration_group_id, sort_order, set_function, date_added) VALUES ('Credit Card Enable Status - VISA', 'CC_ENABLED_VISA', '1', 'Accept VISA 0= off 1= on', '17', '1', 'zen_cfg_select_option(array(\'0\', \'1\'), ', now());