The categories of atheist and theist are mutually exclusive; what you're saying is illogical. There's really nothing to discuss, you're objectively incorrect.
Theists aren't atheists, no. Despite this, an atheist and a theist will often have
the same attitude and beliefs about most gods.
There's nothing illogical about pointing this out. In fact, it's a call to logical consistency on the part of theists, especially monotheists.
If they had bothered to think about it a bit, they would realize that it's hypocritical for them to condemn atheists for dismissing their God without considering it "enough," even though they dismiss countless gods of other traditions without a second thought.
... or they'd realize that when they say "you can't prove a negative" or "absence of evidence isn't evidence of absence" to an atheist who believes no gods exist, they're also condemning their own belief that
no more than one god exists.
So that's what it is. A call to empathy and consistency instead of hypocrisy.
Edit: of course, for this to work, the theist has to be interested in empathy and understanding. This may be why you're having trouble with it.