"I'll keep trying - maybe someone at Google could help?"

Doubtful. Getting support from Google is pretty much impossible (you do have slightly increased chances since you've put it on HN however).

If I were you, I'd initiate a domain transfer to a different registrar that will actually provide support when you need it before your domain expires.

Even if you're lucky enough to have Google resolve the issue this time, you may not be so lucky in the future and there are numerous domain registrars that would handle your domain better than Google will.