Refund on out of stock item

I have been purchasing items from groupon on a quite regular basis. I have purchased a rug as well as 7 piece bedset. When i enquired as to why i havent received the items. I was told the rug was out of stock and i simply never received any feedback on the duvet set. I contacted groupon via telephone as well as email and was told my refund will be done. This process started in August 2015 and i have yet to receive my refund as well as my bedset. I'm very disappointed to be treated in this manner and simply be ignored and i am one of their regular clients. It seems like once you've purchased something and it is out of stock you can kiss your money good bye. Nobody even bothered to let me kno the item is out of stock. The matter was simply ignored. And everytime i enquired i was told they are working on resolving the matter. The last email i received i was told the refund will be done within 3 hours. It's more then a month later and nothing has happened. Im simply tired making telephone calls snd writing emails to them. This is not the way to treat your regular clients or any client for that matter. It is simply unacceptable.