RackNerd halved my VPS cores with no warning. Got them back, but my one question went unanswered

I have a 6-core KVM VPS with RackNerd.

What happened:

• A few days before, I asked sales about upgrading. They offered extra cores at $9/year each. Nothing was said about my usage.
• Then the VPS restarted with half its cores. A minute later a ticket said my CPU use "far exceeds any definition of fair share" and that the cores were temporarily reduced. It was the first message I had ever received from RackNerd about CPU. I checked every email in my client area.
• I replied with what runs on the server and the CPU caps I had already set, and asked one question: how much sustained CPU is allowed on a 6-core plan, so I can stay below it.
• A couple of hours later the cores were restored, thank you. But both of my tickets got the same template reply: run "top -c", consider installing sysstat (I had just told them I already use sysstat). My question was not answered.

To be fair about my side: my usage was high and steady, not a spike. sysstat shows a daily average of 25-42% of the 6 cores on each of the 8 days my logs cover. I would have capped it the same day if anyone had asked. Since adding the caps it has been around 22-26%.

The only number I could find is from a thread here in Feb 2025, where a user posted an answer he got from RackNerd: averaged over a month, at or below 30% should be no problem.

1. Is cutting cores first and telling the customer afterwards the normal process?
2. Is 30% averaged over a month still the rule? If so, why not say it in the ticket?
3. Has anyone gotten a real number from support?