There is no productive argument with someone committed to misunderstanding every clarification.

If every clarification is met with a new distortion, the exchange is not a disagreement, and treating it as one will exhaust you. Some people are not trying to arrive anywhere, and continuing to explain simply provides more material.

You are allowed to stop. Say clearly what you meant, once, and then leave it. Withdrawing from a conversation that cannot go anywhere is not defeat, and staying in it does not become effective through persistence.