Not delivered on time

I was supposed to receive an overnight package today, sent from King William's Town yesterday. I waited all day and laye afternoon my mother phoned the King William's Town branch asking them why the package had not yet been delivered to me in Bloemfontein. The gentleman phoned the Bloemfontein branch and the courier told him that they had went to another address because the driver did not read the address correctly. The depot in Bloemfontein was supposed to contact me to arrange what we could do since it was already 16h30 but no one phoned until the gentleman from KWT insisted they phone me. They did and I told them to deliver it at my residence since I was about to leave the office. I waited until 18h00 but no one came. This is the 3rd time PostNet does not deliver on time. Why are we paying ridiculous amounts of money for overnight delivery and then not get it on time? Why do the drivers only read what they want and deliver at wrong addresses? I thought the Post Office had horrible service but clearly PostNet is worse.