Reverses a transaction when MAC validation fails.
[VB.NET] Public Sub MACReversal()
[C#] public void MACReversal();
After sending a transaction with the Authorize method, the MACValue must be validated against the GetResponseDataToMAC using the PIN pad device's MAC functionality. It must be validated under the latest MACKey returned from Paymentech. If the MACValue cannot be validated, you should immediately send a MACReversal to void the authorization. Note that you do not need to calculate a new MACValue for a MACReversal. You may simply send the MACValue from the original authorization request (the Paymentech server will not validate the MACValue). All other properties must match the properties sent during the original authorization, including the EncryptedPIN, CardTrack2Data, and EncryptedKeyIndex.