GROUPONS EXCUSES ON PASSING CREDIT

I purchased a product from Groupon in July 2015, on delivery the item was found defective. It was returned to Groupon immediately. Its now September and I am still waiting for a credit to be passed. I requested a voucher rather than a cash credit as my credit card that I purchased with was replaced in the beginning of August as the expiry date was near. I asked for a voucher so I could put it against another purchase. They have now said that I have to go into a bank and get a formal letter from FNB stating that the card was replaced. This is ridiculous as my times is already limited and a voucher is all I request. (no brainer that I would then HAVE to purchase again)<br> <br> This is my 2nd purchase which Groupon and my 2nd bad experience. I can assure you that this is now my last experience with Groupon. I will most certainly not be dealing with them again.