Amazon review: Lack of access to kindle technical support

Faulty kindle was replaced by seller under my 2 year guarantee. Newly registered 3574 books shown in library - none showing read status which means no bookmarks- which I use for study- available. Spent an hour with the sellers kindle technician who came to the conclusion it was a cloud interface issue which was an Smazon responsibility. After many hours of not being able to contact Amazon customer service I found a WhatsApp number. Quick response saying issue had been escalated ant they would be in touch. Nothing - messaged again to not that messages no longer have the 2 ticks indicating delivery. Tried ringing the number - no reply. My library has been accumulated of many years. The bookmarks and read status are critical to me. It’s horrifying that unless it is about a recent order, showing on their screen you cannot make contact. The call back requests are cancelled immediately too!