Abebooks Conflicting delivery information and still no delivery Minnesota

I order all of my college books online.  However, this has been the worst buying experience I have ever had.  Abebooks has horrible customer service and they lie.  I ordered my books over 2 weeks ago.  They said it would take 5-14 days for me to receive my books.  The post office shows it takes 3 days to get it to my state from theirs, so I didn't think it was a big deal.  5 days later I get a shippment confirmation, it gave me a tracking number and stated it could take two days for the tracking number to show up in the system.  When I went to track the books, nothing came up.  I emailed customer service to inquire about it.  They told me that my book was shipped 2 days after I ordered it (even though it wasn't sent until 5 days after I ordered it), they also told me it could take 16 days to get the book, and they told me that the tracking number could not be tracked until delivery.  They told me that they shipped the books USPS, however the tracking number and the confirmation email said it was shipped using DHL.  To sum it up, they lied about when it was shipped by 3 days, they lied about what carrier they used, they are now changing the date of delivery, and it has taken over two weeks to get something that should have taken 3 days (per the United States Post Office).  Customer service is not giving me any answers at all. In fact the last two emails I have sent started with, "You have not answered any of my questions."  I bought books to study for my GMAT exam to get into the Masters program at my college, I have now lost out on 24 hours of studying for the test, which is quite a bit of time.  This book was about $3 cheaper on their site.  This was the worst purchase I have ever made!!