verifyTXN method
To verify a transaction, i.e if it was a success, failure or still pending use the method verifyTXN().
The verifyTXN() has 1 parameter verifyTXN(txRef).
Where;
txRef: is a String specifying the transaction reference usually in the format "MC-XXXXXX"
Implementation
String verifyTXN(String txRef) {
return verifyTXNReq(txRef, secretKey);
}