Poor service

I ordered some goods from Hi-Fi Corp almost 2 weeks ago. I received a mail from them a couple of days after placing the order stating that one of the items were out of stock but they did not indicate which one. After this I decided to call to find out what was causing the delay and they advised that an iron I ordered was no longer in stock. I advised them to please send the rest of the goods as I didn't want to wait for an entire order because of such a small item. Since then I have been advised that order was dispatched and is with FedEx. Days of calling after Hi-Fi asking about progress and their sales manager Sharon (Secunda branch) just says she will call me back and never does and I've left numerous messages. After calling FedEx they advised that the parcel was never collected by them. I am left frustrated not knowing where my items are and Hi-Fi Corp not getting back to me. On top of that I have been given store credit for the item that is out of stock even though the item was on sale at the time and the actual price is much more. Why did they not state item out of stock then I would not have ordered it in the first place. I have paid and I haven't received anything.