Check your wallets
Talk to any storage vendor (for instance) and ask them about the customers they've signed up due to Amazon billing practices. There is a long list of Amazon account managers whose sole job is resolving billing disputes. And not small ones. There is a significant flow of ex-AWS customers going back to in-house.
It's not fraud. It's just incompetence.
Some customers have to run Google database analysis on their Amazon monthly bills. They are that big.