POST OFFICE RIPS US OFF BUT THEY DON'T DELIVER

I posted a parcel to an overseas country on the 6th May 2015. I was told that it would take 10 days and was charged a small fortune for it. Today, the 5th day and no one know where the parcel is? I have been on the phone for 50 minutes ***) and no one is available to answer? Ridiculous service. I want an answer or my money back. I called the Meyersdal branch on Friday and asked to speak to the Post Master but was told that she was not in. I called again today and she again is not in. I need answers. It is not the first time that this happens. It's always the same thing. I pay for a delivery within 10 days and the parcel only gets delivered 20 or 22 days later? WHYYY? If this parcel is not delivered on time I demand my money back. I've now been on the phone waiting for 54 minutes. And the message playing in the background states that my call is important to you? Nothing is important to you. Give me my money back. My money is important to me.