This is just inaccurate. I did not say you committed an error within logic. I pointed out that we have no scientific means of identifying consciousness, and that you can't use logic effectively if you can't identify unprovable states. Everything else you've added is outside the scope of what I said, and kind of makes my point for me.
The problem with your "proof" is that it is logically accurate. "If an AI can be abused by cruel language, then using it is unethical because it's operating in a condition of slavery." Logically sound. Combine that with the opposite and make the excluded middle - congrats - you've just demonstrated why logic doesn't work for this entire domain of problem.
In order for your argument to work, you have rely on the cultural assumption that because slavery is unacceptable between humans, it is necessarily bad in all domains; but "slavery" is entirely subjective. As an example: you cannot logically prove whether or not keeping a pet dog is "slavery" or "unethical"; the answer depends on how the dog experiences it. Technically, we have no way of actually proving whether AIs (or even dogs) have experiences, and if so, whether or not "slavery" is a problem for them. Those are subjective problems that require details logic can't provide.
Strictly speaking, the only thing I'm claiming here is that the TOS is logically indefensible, but so are the objections to it.