That is the free tier. The fix is very simple. You add a credit card but not go over the free tier usage limits. Then they don't touch your stuff and you still don't pay anything. (Free tier applies to everyone including paying customers)
What can go wrong with a single VM? Billing explosions in the cloud are always to do with auto-scaling services that go wrong. Plus, in that case your alternative is fighting Microsoft, Google or Amazon.
If you run the free tier until the intro period ends you'll know exactly what you can run for free. (There are some free credits during the trial that might skew the resurls) If you do not add anything extra after rhat, there's no visible way you can have a bill larger than 0. But you have to pay attention. Whereas before you would be told "you can't do that", later it'll just go through.
Though there are no other cloud hosting providers that give you VPS with public IP and 24GB RAM for free. Oracle did shutdown my VM like 2 times in 3 years, but considering I paid them $0 it's borderline awesome service.
Sounds like you got further than me, they simply permabanned my payment information (also cannot complain too much since i didn’t pay a dime either, but seriously?!)
IDK, their support is pretty responsive and the only requirement they have is that you must sign up using actual credit card and not some prepaid / debit one.
No I did not, but I dont host my mail on their servers either. I still used it quite extensively and it's far more reliable than 99% of cheap cloud providers.
I mostly use them as my personal build server and VPN.