Order has been dispatched - Not in stock

I ordered a proline ceramic hair straightener brush online, my mother also ordered 2. On the 26th I got an email that said your order is on its way, has been dispatched, 3-5 working days. I called 5 times to follow up on where the order is, but it's the same story every time, they have to call the warehouse to find out whats going on and will call me back, they never called back ONCE! On the 5th time my colleague called, and the woman said there's no stock and she will send me a email to get a refund. Still nothing. Worst service ever and we are still struggling to get our refunds. I don't understand why they don't say no stock available if you order and pay for it online.