The market solves this problem without any government interference at all.
Fraud is always illegal. Now that the G is involved you'll see even more collusion and higher prices.
If there's no standard, there's no fraud. Currently, from a legal perspective, "extra virgin" has the same legal relevance as "tasty". It's meaningless. Are you going to sue someone for fraud if your snack isn't "tasty", although that's how it was marketed? You might, but you won't prevail at trial.
Since there's no legal standard defining what is or is not "extra virgin", everything is extra virgin. You have no basis for a fraud claim, even if what you were sold isn't remotely extra virgin.