Incorrect cost £/100ml

why are many of your spirits showing incorrect unit cost/100ml. this is not regarding special storecard offers, it a simple case of BAD coding . you manage to get some correct but there doesn't appear to be any logic or theme for those you a quoting wrong. the equation to calculate this NEVER changes so how can you possibly make such basic error ??? if a store website got them wrong like you are, I'm sure they would have trading standards crawling all over them. eg Asda 1ltr Gordons London Gin @£18 is 0.18/100ml NOT 0.23