Amazon Amazon fails to provide prime benefits for prime members Internet

Amazon has a service called Amazon prime which requires a yearly membership fee paid in advance. I have been a prime member for several years. One of the benefits is free 2 day shipping on eligible items and discounted overnight shipping on eligible items. During the past two years, with the most recent case being today Friday, September 19, I have paid for items to be shipped to me either overnight or with my two day shipping benefit and Amazon has failed to get me my item in time. Only one of these several times was it a question of whether it was Amazon's fault or the shipping companies, every other time it was because Amazon simply did not ship my item until after I contacted them (on the day that my account said GUARANTEED delivery date, I have screen shots as proof). Every time they are unable to give me adequate reason why I am paying for a service and for items in advance to get them by a certain time and Amazon is simply failing to ship them in time. They will not give me a reason. In the case of paying the money for overnight shipping I have been refunded, however this doesnt cover any of the yearly membership I pay to get discounted overnight shipping. In the case of two day shipping not getting to me they simply tell me to wait FIVE DAYS past when I contacted them (I have already waited the two days it was supposed to take to ship). They will not provide me with a reason why I need to wait five days when (according to what they promise me with my prime benefits and the information on the item's page) I could literally reorder the item and it should get to me within TWO days. They avoid all questions relating to why they have not shipped my items on time and why they are still waiting to ship my item(s). Amazon prime is a scam.