Have you ever bought or sold anything on eBay or a similar website? What did you buy or sell?
...
Have you ever bought something online and had a problem with it? What did yo do?
...
Have you ever got to the supermarket checkout and then found you didn't have enough money? What did you do?
...
Have you ever lost a bank card? Where did you lose it?Did you get it back?
...
Have you ever tried to take something back to a shop without the receipt? Did they change it?
...
Have you ever had an argument with a shop assistant? What was it about?
...
