Just got DCCed at Armazem Do Bacalhau in Porto. Credit card machine screen showed €18.50, so I tap my Chase business card. However, when the receipt came out, it was billed with a 5% markup as USD 21.06. I was never given or even shown any options. I requested the card to be re-done in EUR but merchant refused. How do I avoid DCC on this tap system in the future? Is it a good idea to dispute the transaction with Chase even though the differrnce is only $1 and to request to be billed in local currency?

I also got DCCed at Pasteis de Belem - similar situation. I tapped my credit card on the machine, wasn't given currency option and €10.10 suddenly came with a 4% markup converted to USD 11.37!