i didn't know the merchants would have to pay if you made a chargeback.
i feel bad i made one accidentally for the taxi cab because i thought they artificially increased my tip. i was on my was to the hospital and on pain pills so that's how i remembered it at least. then i found the receipt in my jeans pocket later on and that was the amount they charged me on my credit card, i just thought the amount was different.
that means i cost them the $15 for the cab and another $50 for the taxi. i know it was an accident but i feel kinda crappy about that.