I went shopping yesterday and bought four things from a shop that were £10.90 each, knew it was going to be over the contactless limit so put my PIN in and didn't check the amount, got home and looked at the receipt which makes no sense as the main receipt has the right amount on it and the card receipt has this random number on it which is wrong, and just checked my bank online and I was only charged £10.60 for the whole lot. I am confused as to how this could happen and I don't know what to do as I can't go back there in the foreseeable future due to work.