The EFSNet site suggests a solution to your problem. Did you experiment with the SOAP::Lite code samples provided by them:

# Note: To use this sample, insert your issued StoreID and StoreKey va
+lues where appropriate.

# This sample Perl code demonstrates calling the EFSnet SystemCheck me
+thod via the SOAP interface.
# This code requires SOAP::Lite and its pre-requisites (http://www.soa
+plite.com/).

use SOAP::Lite;

# Call EFSnet SystemCheck method
@OutputParams = SOAP::Lite
-> service('https://testefsnet.concordebiz.com/EFSnet2.wsdl')
-> SystemCheck('myStoreID', 'myStoreKey', 'EFSnet samples 1.0');

# Get output variables
$ResponseCode = $OutputParams[0];
$ResultCode = $OutputParams[1];
$ResultMessage = $OutputParams[2];
[download]