Continuously extending delevery date

On the 3rd of Feb I order a book that I require for my studies the delivery date for this book was scheduled for the 27th of Feb. On the 26th of Feb I received an email stating that the book will only be delivered on the 6th of March (I was ok with this since it will give me enough time to study for the test that I am writing on the 11th of March). Yesterday I spoke to somebody from Kalahari to confirm the delivery date is still the 6th, I was then informed that the parcel was in JHB (so it just need to be package and delivered to me in Kempton) then received another email stating that the book will be delivered on the 10th, I called Kalahari again because I need the book that person said he is going to speak to one of the managers to see if they can get the book delivered by the 6th and he will call me back (I an still waiting for that to happen). This afternoon I call again to find out what is happening, there is still no feed back they will find out what is happening and get back to me. At 15:50 I receive another email saying that my book will be delivered on the 12th. again I call and they will come back to me. this is unacceptable. How am I supposed to write test