NAB Transact - How to process a refund with Omnipay

Question

We are using Omnipay for NAB Transact.

https://github.com/sudiptpa/omnipay-nabtransact

We can successfully make payments and we can see amount in back with transaction id etc.

Now we are trying to refund so according to documentation its need below parameters 'amount', 'transactionId', 'transactionReference'

and our code is

$refund = $gateway->refund([
                   'transactionReference' => "XYZ100",
                   'transactionId' => "245294",
                   'amount' => "10.00"
                    ]);

$response =  $refund ->send();

In response we are seeing this message

Credit card details not available

Can some one help with it.

Thanks in Advance