Refund not being processed

I ordered a dress online from spree on the 4th of December 2017 and got an email which confirmed my order. A few moments later I got another email which said I caught them at their worst as the item is in fact, out of stock and I have been given store credit with the amount I had initially spent. It went on to say that if I wanted the money to be refunded I should email and say so. Of which I did and got an automated response which said they are attending to my issue. A few weeks passed and I contacted Spree support via Twitter, 1st time I got no response and the second time I did. A lady called Aviwe assured me that I would get the money credited back in to my account (this is now on the 20th of December 2017). No credit yet so I contacted them again via Twitter and this time I got no response. I just want my cash refunded back to me... Not store credit. I shouldn't have to be forced to buy something else I do not want, simply because they are not refunding my money.