I doubt that...but, give it a try.
Okay, within reason, I can do the same...although Richard Feynman would probably disagree with us. He often noted that "proving" something involved a much more rigorous process than most people suppose. But as I said within reason, I can do the same.
So what?
Well, I doubt anyone could prove that something doesn't exist...except for direct contradictions.
SO ANYONE STUPID ENOUGH TO ASSERT THAT SOMETHING DOES NOT EXIST...PLACES HIM/HERSELF IN THE POSITION YOU FIND YOURSELF IN.
Shit out of luck...and often, as in your case, not ethical enough to concede the error.
An intelligent person realizes he cannot PROVE something does not exist...and doesn't proclaim his/her ignorance by making such an assertion...
...the way you did.
Anything else I can help you with?