"You ate well, that is the payment," said the mango woman

I bought mangos at the Mercado Municipal Rio Cuale on Saturday, and when I got home I realised she had given me five and charged me for two. Next morning I went back with the extra money. She waved it away and said, you ate well, that is the payment. I bought a bag of limes anyway and she added two without asking. This has been going on for a month. I now take home more fruit than I can eat. I would like to stop. I do not think I can.