Yes I know weve read that but the problem is we're not getting what that page says were entitled to so what do we do?

Hi I'm representing a group of employees at my retail workplace some of which are part time and some are full time. The shifts we do vary between 4 and 12 hours a day. It is an individual business not part of a chain or anything. There is no union or HR department there are just the managers who own the business and about 20 staff who work for them. The problem is that we are not allowed to take any rest breaks even in 12 hour shifts. We have previously been allowed a few minutes to eat a meal at some point during the shift but we have to stay at our workplace and if the phone rings we have to leave our meal to answer it or if a customer needs serving we have to serve them. Often our food is left to go cold before we can get back to finish it. The new problem is that we have seen an email between the managers complaining about staff eating during their shift and it shouldnt be allowed as it looks bad to the customers (the email wasn't meant to be seen by us but one of the managers left it on screen on a computer in a public office. They dont know we have read it and ok maybe we shouldn't have if it wasn't addressed to us but we have and its about us anyway). So one of us contacted acas and all they said was there is nothing they can do as there is no way to enforce it. Then we contacted HSE who were very understanding and they passed it on to our local council. Although we have since contacted the council who have said they have been in to speak to one of the managers and they are not going to take any action because they pay us for the whole shift (like if we work from 7am to 7pm straight we get paid for 12 hours. they would only take action if they stopped our pay for a rest break but didn't allow us to take it). We don't think this is fair but we really don't know what to do about it so we are hoping someone on here can advise us on what to do. Other people have said just leave and work somewhere else but it's not as simple for that for some of us who can't find a different job. Thankyou