"I missed an email that had important in the title because I didn't think it was important, now my servers are suspended and it's all Google's fault". Makes sense, I'm sure you'll fare better with Amazon.
The OP certainly has some culpability but having bad experience of this process myself multiple times, it does feel as if Google designed it to be hostile — the emails being just one part of it.
Google Cloud is great in many ways, I love the product, but the billing is such a pain, top to bottom.