Out of stock item not refunded after online purchase

I ordered a baby cot and a couple of other small things online because I needed the cot urgently. The other items were delivered but the cot did not get delivered and nobody bothered to inform me about the reason why until i called 4 days later. I was told the cot was out of stock and that my money for it would be refunded. I still have not got the refund! I call everyday to ask about updates and they tell me they will call me back and they never do. This is very annoying and frustrating for me to be chasing after my money! I will never buy from mr price ever again and wouldn’t even recommend anyone else to do so especially online! Terrible service! And on top of that i still got charged R350 for delivery! Had it not been for the cot i wouldve just bought the small stuff in a store. And whats the point of delivering a cot mattress when theres no cot! Why allow someone to purchase something online and even charge them if its not on stock?!!!???