We went to moondog's ABC place. And also BoC place. We managed to fix the BoC but couldn't get to work on the ABC place. I'll recount the latter first.

ABC shop

Me: (picking up a can of soda water, moondog picks a bottle of vitamin water) "they take visa for this? If we tried this in hk we'd be told off!"
Moondog: "it doesn't cost them! They take it even for one bottle."
(We walk the can and bottle to pay. They are RMB10. Moondog hands over his Visa card.)
Cashier points to visa hologram: "this one? We're no longer accepting this"
Me: (to moondog) "you know her? She knows about the DCC problem?"
Moondog: "yeah I'm buying stuff from her every week!"
Me: (to cashier) "why?"
Cashier: "cos a. we have to pay fee for visa and b. your friend over there told me off for crap exchange rate!"
Me: (to moondog) "so she does know you!"
Me: (to cashier) (showing BoC exchange rate shot below) "so is there any similar screen in your ABC terminal?"
Cashier looks at my photo: "No. No such display"
Me: "tell you what" (handing over my HSBC visa). "Swipe this, cancel this straight after and I will cash you out"
Cashier: "what do you mean?"
Me: "well, after you charged this visa rmb10, can you void it?"
Cashier: "no, I don't know how to void."
Me: (to moondog) "I think the experiment has to stop here. She's not as comfortable as the BoC guy with us mucking around the terminal, and if she doesn't know how to void then she has to pay the fee even if we're fine paying inflated rates on RMB10"
(We paid RMB10 in cash and left)