GROUPON NOT REFUNDING OVER RECOVERED FUNDS

I bought a product on line and the payment went through twice on my credit card. I send e-mails to Groupon's customer support but the only reply I received was an automated reponse that they have high volumes to attend to and will get back to me. This was the 29th April 2015 and to date I had no response from Groupon or refund from them. Even if I don't get my money back I will never buy from them again.