I went over and she said something more which I also didn't get. I apologized and said I didn't understand. (I say this a lot!) Then she seemed ... not apologetic, but more relaxed. She checked that I spoke English and then searched for the right words in English but couldn't find them.
In French, I made sure that it was okay that I bought the mandarins. (It was a fruit shop after all.) And bananas too. Then I spotted some grapes and grabbed them as well. As I paid, she asked if I would understand if she spoke slowly. I ventured to say "Oui", although it was far from certain that I would.
Then it came out (calmly now) that I had failed to say "Bonjour" when I entered her shop. I gathered that it had been impolite of me - and she felt justified in reprimanding me for it. It was her shop after all.
I remember being told, years ago, about this difference in the customer-shopkeeper relationship. In Canada, we tend to think of the shopkeeper as being involved in the service industry and is there to help the customer, being rewarded with a sale: the customer has money and the shopkeeper would like to get it. In France (I was once told, and this experience seems to confirm it), it is the opposite: the shopkeeper has some wares and the customer would like to get some. Of course, in both countries, it's win-win when you buy something.