I actualy use some space there for backup. Cost me $2.70 for June 2020 for the first time.
As you can see on the pic my available credit is $0. What the hell?! Bildschirmfoto von 2020-07-02 10-51-15|690x281
This is not something forum users can help you out with I’m afraid. But I’m sure support will help you just fine. It can help to link to this topic so they have the screenshots etc as well. And do report back what your experience was!
As far as I know, you will be post-charged at the end of the billing period.
Are you sure, that you charged to $50? I do not see that in your posted billing history.
Perhaps you confused the charging with expired promo credits? When you opened an account before the production launch there was a promo credit for $55 with expiration date for two billing cycles since the production launch.
When it expires, it is no longer displayed in the balance on the billing page. But it doesn’t mean that you paying that sum.