Fees may now be paid only at Citibank in either Cristobal or Balboa, and no longer direct to the Panama Canal Commission. Payments can be made only in cash, bank transfer or VISA credit card. In Cristobal, the office is on the second floor, Administration Building, No. 1105, and in Balboa, first floor, Building 729. An appointment will be made to visit the boat.
Maybe it's just the bank, but I think someplace else it mentions it's faster to get a refund if you use citibank visa for the deposit