Your money is not welcome here....

My Greek mother-in-law visited us in Sweden for the Christmas/New year holidays and all the family, with my mother-in-law as the first victim, got the flu. Except me. So, when all were tucked in bed and I was at work she thought that the refrigerator was empty. So she went to the store to buy some food. She does not speak English and no Swedish so that was a rather brave move. She took some food to the cashier and the staff started to say something to her and refused her money. My mother-in-law got scared and thought that they were going to contact the police as the money must be fake. She had exchanged the money in Greece in their local bank office. The supermarket staff started to choose some money from her hand and she could pay with those notes the others they did not accept. She returned with the food but was very upset. I have forged/fake money! When I came home from work I checked the money. It turned out that the money were not fake but some notes were not valid anymore. So her bank had given her money which were not valid anymore.....