If the card is an AMEX or Discover card, the merchant account may not be setup to accept those card types. Call NaBanco and have the merchant account configured to accept AMEX and/or Discover.
Verify, with NaBanco, all the extended information entered into PCCharge (Setup/Credit Card Company/Extended or Setup/Merchant Setup/Setup Wizard, then click Next twice). Pay special attention to the Serial Number (must be 4 digits) and the Qual Code (must be 5 digits). Both the Serial Number and the Qual Code must be entered. | 
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