Fair enough, thank you for explaining. Will definitely contact citizens advice.Any employer worth their salt will respect you wanting to protect your own interests. @Highland Mule is correct in what he says. There is also a legal position here that an employer MUST follow and it appears they haven't . If in the next 6yrs they get a HMRC inspection and they discover that the rule of law has not been followed then there will also be implications for you. The law is .....and I'm happy to be challenged, that it is as much the employees responsibility to make sure the law is carried out as much as the employer. .....
Take the advice given and see Citizens Advice and cover your own back !