If true, I'd check all configured email addresses. They let you configure different addresses for support/bills etc. and will send warnings only to certain addresses.
Hetzner is usually good at revolving issues.
If you don't pay a bill, they eventually will block incoming traffic from the web. They are still reachable from inside hetzner network and they will unblock traffic as soon it's paid.
If the BSI finds Ports that shouldn't be open to the public, they will forward the mail to you and won't take actions.
If you disturb their network due to misconfiguration, they will block you, demand an explanation within 24 or 48 hours and unblock you, if they find it plausible.
If you call them with technical issues - in my experience - you typically want to prepare logs, traceroutes etc. because they will know enough to provide guidance on how to resolve it.