Were you using Visa or Master Card credit cards or debit cards (I don't know if it makes any difference and I am unfamiliar with debit cards)?

When we were in Paris several years ago we had a terrible time using either a Visa or Master Card for paying anything under (I think) $20 or maybe more. We had to go to the American Express to cash a check because we ran out of money. One nice thing about going to the American Express office in Paris is that it is very near Harry's American Bar

We found the UK to be much more user friendly about accepting credit cards.

Chris in Pearland, TX