Refund request

I was at the Greenstone branch on the 8th February 2016. I booked tickets and when my card was swiped the system had an error and said that the transaction must be redone, which it was. I received 2 messages for the two swipes but trusted that my account would be rectified as the machine said it was an error. Upon checking later this was not the case and both transactions went through. I contact the head office and spoke with Vijien, she asked me to send her proof of the transaction (bank statement) which I did a few times but have not yet had a response. Please could some urgently help me sort this out and get my refund.