Delivery incompetence

My parcel was out for delivery on Thursday 29th November. Never received it. Then according to the tracking system it was back at the courier company on Thursday. Called on Friday around noon and was told they will follow up and call me back. At around 15:30 I called back because no one had called me and was told that it would definitely not be delivered today (Friday) but instead on Monday. This, to me, meant I could leave the office as my delivery was confirmed for Monday. Around 16:30 on Friday, as I was almost reaching home I receive a call that my delivery is at the office. I was extremely happy to wait for my delivery until the close of business if I had not been incorrectly advised that my delivery is confirmed for Monday. Now I call in to find out where my order is and they tell me it's with the courier company because our office mailroom does not have it. Where is my order Incredible Confusion?