DHL is unorganized chaos!

Very disappointed with this company! I recieved a notification last week that a parcel I have been waiting for will be delivered to my adress, as provided by the seller of the parcel, between 2 and 5 this afternoon. I had gone online to accept this time, and proceeded to cancel all my appointments so that I can be home to sign for the package. At 14h00 today I recieved an sms saying that the parcel couldn't be delivered. I called the number provided in the sms, and the operator informed me that the postal code was incorrect, so they couldn't deliver the parcel??! My full adress is with DHL, my city, area, and full street adress is available to them, but the incorrect POSTAL CODE caused them to not find my house? I was then promised, after speaking to the driver, that my parcel will be delivered before 5. 5 oclock comes, and I still haven't recieved the parcel. Then I call them again, only being told that the Postal code was incorrect, so therefore they cannot find my house!! This is AFTER I was promised that the package will be delivered today! I have now wasted my entire day, and have come no further in ascertaining when the parcel will be delivered to me, as the 'matter has now been forwarded to a managing department, who will get hold of me' So how do I now plan my day tomorrow? Absolute junk for service, I am so disappointed with this company who I thought was the best, when suggesting to the seller of this parcel to use DHL. Never again!