In the past I almost move to Hetzner but fortunate I found some really worrying posts: hetzner banned account - Google Search
I don’t think you will get back your account or data (backup).
I would look for a new service provider and restore the most recent backup I have. Once it’s done set up: Configure an S3 compatible object storage provider for uploads
Make everything safe as possible!
I think it’s better to lose some data than do nothing and wait. The website must be available no matter how but people should access it. Bad things happens but you should handle and solve it as soon as possible everybody learns from this kind of things. Your community will understand it and you should give some compensation to your users and create a topic where you explain this situation.
You can also put it in read only mode and put a global notice while you see any chance to get back your backup if it happens you can restore it.