Moneris Refund Not Working In PHP api

Hi All,

 I am using a sandbox account.   I just make a test purchase using sandbox account and it shows the response message as "approved" . After that I am using the same orderid for test refund option.But it shows some  error  like "DBRequestCalls:createRefundInfoArray, Nothing returned from the query". Why this error occured.  Is this issue occured because of sandbox account? Please help

Here is the response array 

   [responseData] => Array
        (
            [ReceiptId] => null
            [ReferenceNum] => null
            [ResponseCode] => null
            [ISO] => null
            [AuthCode] => null
            [TransTime] => null
            [TransDate] => null
            [TransType] => null
            [Complete] => false
            [Message] => DBRequestCalls:createRefundInfoArray, Nothing returned from the query
            [TransAmount] => null
            [CardType] => null
            [TransID] => null
            [TimedOut] => false
            [Ticket] => null
            [IsVisaDebit] => false
        )