Inaccurate tracking system, hard to contact

I'm shocked by my experience with amazon, I ordered a lot of items through them for Christmas as I have ordered multiple items successfully over the last few years, I became concerned on this occasion as a large number of orders consisting of multiple individual items showed as being delivered but had not arrived although a number of items had arrived that were still showing as in transit. It appeared to me to be an obvious administrative error but I was concerned about it as I was worried in case any of the items showing as already delivered did not arrive at all. It was extremely hard to contact customer services and when I eventually got on the chat line I felt the assistant did not seem to fully understand the problem and made me feel dishonest, I received no reassurance whatsoever, I have spent thousands of pounds through this website over the years and had placed my order quite confidently. After years of thinking amazon was a great website and a first point of call for purchases I now have little confidence in ordering through them anymore after this experience.