Taking unofficial break
Learn which manager is rather flexible and when to slip out unseen. Use the toilets more frequently than normal. Join the smokers (effects of passive smoking). Keep unopened food on the table in front of you proving you only come on break. If it is after the usual break time, reason that you are late because you have been helping a customer. Remember that any seasoned manager knows the scams and you may be invited to a disciplinary meeting with your boss. You couldn't win the war with set break time.