You do not need closure from someone who repeatedly gave you evidence.

Sometimes the closure is already in your hands, made of everything you saw over a long period. Waiting for a final conversation to make it official is a way of holding the question open when it has actually been answered many times over.

Count what you already know rather than what you were never told. Write it down if it helps. The evidence you gathered is the closure, and it does not need a ceremony to count.