Sorry, but just throw it away. Your grinder will smell like artificial hazelnut for weeks if you grind it through. It might already be too late.
If it was just a roast you didn't like, there's a lot you can do. But when there's artificial oil on it, you're kind of screwed because that awful smell just lingers.
If it's already too late:
If you drink protein shakes, you could use the coffee with the protein as a workout supplement with caffeine. The artificial flavor will get lost in the artificial flavor of the protein.