post https://secure.vend-o.com/api/gateway/refund
The Refund API allows you to issue either full or partial refunds for a Gateway Payment.
Partial refunds
Any transaction can be refunded in full or in part. To issue a partial refund, use the partial_amount parameter.
Note: Maximum of Two Refunds Per Transaction!
If a transaction is partially refunded, only one more refund can be issued, and it must match the exact remaining amount. In other words, a transaction can only be refunded in two parts: one partial refund and one for the remaining balance. It is not possible to split the refund into three or more parts.
SEPA and refunds
Refunds for SEPA transactions should not be processed. Learn more