Originally Posted by
abaheti
Related question, not quite DCC but this seems like the crowd that would know. Hypothetical: Hotel in Mexico quotes $50 USD for an upgrade. The bill is in pesos, so the hotel picks a terrible conversion rate on the bill, 20% wrong, say. Would a credit card dispute yield any help (quoted $50, but charged $60 is the logic)?
I have only stayed in a few hotels in Mexico, but two Hilton properties, one in Cancun and one in Puerto Vallarta, billed in USD natively without DCC. Some things were priced in MXN, but the hotel ran my card in USD at the point of sale. There was a conversion to MXN that seemed in line with the exchange rate. I don't know if non-local cards are billed in USD as well and only local cards would use MXN. A third hotel billed in MXN.
In the situation you described, you'd have little recourse if the transaction occurred in MXN, but my guess is that the above property might be like those two Hiltons and use USD as the currency denomination.