+=item list_payments HASHREF
+
+Returns a list of all customer payments. Takes a hash reference with a single
+key, session_id.
+
+Returns a hash reference with the following keys:
+
+=over 4
+
+=item error
+
+Empty on success, or an error message on errors
+
+=item payments
+
+Reference to array of hash references with the following keys:
+
+=over 4
+
+=item paynum
+
+Payment #
+
+=item _date
+
+Payument date, in UNIX epoch time
+
+=item date
+
+Payment date, in a human-readable format
+
+=item date_short
+
+Payment date, in a shorter human-readable format
+
+=item paid
+
+Amount paid
+
+=item payby
+
+Payment method: CARD, CHEK (electronic check), or BILL (physical check).
+
+=item paycardtype
+
+Payment card type
+
+=item paymask
+
+Payment card mask
+
+=item processor
+
+Processor for cards and electronic checks
+
+=item auth
+
+Authorization number
+
+=item order_number
+
+Order number
+
+=back
+
+=back
+