I don't blame Amazon here. This is suspicios. All debit cards are linked to your bank account which always have a statement.
Also, I have found it very helpful to provide not just statement but the photos of the card, your ID and various other documentation in the PDF. It helps the support engineer realize that you are really you.
I've sent them the exact documentation they requested (actually well over and above what was required) - all of it rexboxed and annotated, and each time they send it back saying the documentation is illegible or lacking in the details they require.
There'll come a day even the people who defend copyright won't be able to justify supporting this industry due to how badly it mistreats and abuses them. It's simply appalling how it's almost 2022 and paying consumers still get infeiror products and services compared to "pirates".
Just to give a car analogy, imagine your car is at your BMW dealer for repairs. While it is there you buy some new rims and pay with a credit card that is different from the card you used for buying the car. After that they refuse to give you back your car, because they say this is suspicious. Nobody would accept that.
OP clarified that it is not a debit card, it is a prepaid card.