Amazon Account Hacked: Missing Orders, Prime and Alexa Devices Disabled

I have been an Amazon customer for a long time and I rely on my Amazon account, Alexa/Echo devices and Prime Video every day, especially as I am 67 years old and disabled, and spend most of my time at home. Since around Wednesday my whole Amazon system has effectively been turned off and my account appears to have been changed or hacked. On Wednesday I placed an order through Amazon and shortly afterwards I received a phone call from a driver asking to confirm my postcode. I had ordered black bags and then on Thursday I received a delivery of bags. After that, everything went wrong. When I log in to my Amazon account now, my basket is empty, my recent orders have disappeared and the system shows as if I have not ordered anything for about three months, which is not true. My Amazon Prime page is gone and it looks like I have almost no information in my account, even though it still seems to have my email address. At the same time, my Alexa/Echo devices stopped working properly. My Echo Dot is now asking me to re‑register my account, and Alexa and my other connected channels are effectively turned off. Before this problem, everything was linked to my Amazon account and working normally. I have already spoken to Amazon customer service and they told me that everything is fine, but it clearly is not, because my account is blank, my order history is missing and my devices and Prime services are not working. I believe my Amazon account has been hacked or changed in a serious way and this is causing me a lot of distress, because I depend on my television, Prime and Echo devices for everyday life and entertainment as a disabled person. I kindly request that you urgently investigate my account, restore my correct account data and full order history, reactivate my Prime access, and reconnect my Alexa/Echo devices so that everything is returned to the way it was before this incident, and ensure my account is fully secured against any unauthorised access.