Please provide us with the amendment or payment cancellation (please indicate reference number of the payment in the message) and sign the message with digital certificate.
According Bank tariffs, the additional information to the payment will cost 100 EUR, http://www.rietumu.com/fees-payments
Also, You can expect a refund in case the amendment or cancellation will not be sent (the waiting time depends on the recipient's bank).
We include a partial copy of the SWIFT message: