I had a interesting experience in Krakow, Poland today.
Gave my USD card to pay and when the merchant processed the payment, there was no choice for PLN. It auto printed in USD. The receipt did say I was given a choice, which I did not get. I, of course refused the purchase and paid with a PLN card.
Reading the wiki it seems that there are ways to dispute it, but what happens if I have no choice? For instance I am at dinner, and want to pay by card? I ask before that they accept Visa. Can I refuse to pay if I give them my USD based card, it auto prices in USD and the receipt said I was given a choice? The wording on it was "I accept that I have been offered a choice of currencies for payment offered by eservice and that this choice is final. I will have no recourse against payment schemes concerning the currency conversion or its disclosure. I accept the conversion and final amount and that the selected transaction currency is USD"

Has anyone filed a dispute with Chase successfully?