It should go without saying that in so far as it is necessary for you to provide a definition of the subject in your argument, you and I may be understood as not talking about the same thing, ie. your counterargument relies on an equivocation.
In any case, your own argument regarding entropy is correct only to the extent which the glass is treated as a system-in-itself, as the Second Law of Thermodynamics allows decreases in entropy in systems which are not isolated, ie. as one system among many systems, that is as one object among many objects. This functions through the displacement of entropy from one system, the silica and other ingredients, into others, like the air, as part of the forging process. However, this all partakes of a human, object-oriented perspective.
When this perspective is discarded, what is left is the relationship between All-Things, eg. the universe, which from the perspective of the Second Law of Thermodynamics is an isolated system, it's own nature being all encompassing. As required by the Second Law of Thermodynamics, such an isolated system can only increase in entropy, meaning that for the purposes of your definition, there is only Destruction without Creation, and the appearance that Creation has occurred is an illusion produced by the particulars of the human cognition.
However, the moment that we understand Creation as illusory, it ceases to be a thing with which Destruction can engage in a material binary relationship, ie. one outside of destruction as the truth of the lie of creation. The entropy of All-Things increases, uninterrupted and unabated, making Destruction simply the name for the movement of All-Things.
At this point, your Destruction becomes just another word for my Change,
"Things change, but they are never created or destroyed."
And the extent to which you can perceive things as contrary to this is the extent to which you engage with the glass as a thing-unto-itself,
"Because they look and see a world filled with the appearance of things, they mark the comings and goings of these appearances as beginnings and endings, in turn creations and destructions."