Sorry, pal - your original quote was "There's only one way that sales tax is calculated". Perhaps you read that as "one of several ways" as you now try to pretend, but certainly most readers would not. Perhaps in YOUR version of English that means something else, but most would certainly think you were saying "there's only one way" (which you now claim you did not say).
Perhaps it is YOU who has amnesia. And perhaps you don't understand that one of the dictionary definitions of fraud is "an act of deceiving or misrepresenting" which is precisely what you are attempting.
I responded by saying there was no single way and left your obvious statement that there was "only one way" hanging on the fraudulent tree of statements remaining to be justified. You haven't done so.
I don't recognize you as a "voter I'm trying to convince" either. Your opposition to the FairTax is quite clear by your methods.
There is only one way that sales tax is calculated. There are a great many ways it could be, but none of them are actually used. Tax is charged at the register. Please don't embarass yourself by denying that, or pretending it's news to you.