Poor handling of online purchase

After we bought pool loungers online and the purchases were confirmed I made the online payment. A lady called me a week later to confirm that they were out of stock and still waiting for it. Weeks later she called again that there was still no stock and she was not sure if they would get it either. She suggests that they do a refund. After I had to inquire about the refund they send an email saying that they keep it as a credit or I have to come to the store to receive cash. Firstly I bought online because I live 200km plus from Cape Town and secondly it was their fault that there show stock online. This is now the second time I order online and it shows stock when there is none. They have to pay my money back into my account, I already had to order and pay at another store.