I used to get 100% of my Amazon deliveries before they started using the postal service. Now it’s totally hit or miss.
I called the USPS and got the same message (over 1 hour wait time). SO I called Amazon, which picked up in 5 minutes I told them I was just going to order the same item from another vendor that doesn’t use the USPS and they agreed and said it’s your option to just refuse the USPS delivery if and when it ever comes. So that’s the solution.
It took some real work, but I managed to get all Amazon deliveries UPS or FedEx. No USPS is a shipping option. You need to really work Amazon over with enough proof of losses and proven screwings. It took two months.