5) Poison the Well.
This is another favorite of the Calvinist. If they cannot refute you, they can simply compare you to the “heresy de jure” in which, if you disagree with the Calvinist, then you are...a Universalist, Pelagian, Semi-Pelagian, Romanist, Liberal, ect. (Of course, as an Arminian, I would point out that the Gnostics also denied Free Will, and affirmed Determinism, in which “Augustine” was a former Gnostic for a decade until his conversion to Catholicism, but at least there is a common bond between the two, in which both denied free will. That’s at least a fair point to make.)