Tough call. If you had responded to his suggestion that you just see each other as friends, with 'No thanks. I'm not interested, I would say just ignore.
He may be incredibly dense so maybe a text 'I don't want to see you again. Stop contacting me.' is in order.
However, I think you were clear enough that a normal guy might call you again, maybe even two times over a week or two, but get the hint. This guy never stops and texts at 5:30 am. That is rude and major boundary busting.
