go back asap they have to tally their tills up after every shift, also be careful and watch they don't cover the total screens up, many shops do, it's a trick, sometimes they give you two receipts to confuse you, (old trick i've got caught. (in the uk they ask do you want cash back with your shop and they pretend to forget to give you the money, i don't think you cvan do anything now but this is just a few cons out there especially the coin and note switch. hope this helps Lee from South Wales (celt) UK. (if they undercharged you) (if they've over charged you then think of my above answer.)