Of course Google can restrict how their API is accessed. But locking paid accounts with no warning, no explanation email, and no functioning support path while continuing to charge $249/month is a different problem entirely. A reasonable enforcement process would have been a warning email, grace period to stop using the tool, then restriction.
What an awful way to lose trust, locking out their users but billing them all the same.
What an awful way to lose trust, locking out their users but billing them all the same.