I bought and ipad on the online apple store, on their back to university programme (in the UK). I was overcharged by around £80 (the price of the gift card they gave me as part of the back to university offer, basically the web site charged me for the gift card). I called up their support and explained the situation. For about 10 minutes I had the lady explain to me in the politest tone possible how I didn't understand the calculation, because naturally she believed that the Apple web site wouldn't make a mistake. She finally realised that it was wrong after a while and refunded me really quickly, but I think she could've easily gaslit and anverage person into believing they were in the wrong.