I appreciate your opinion but it occurs to me that the answer to that problem is not simply to say 'no, thank you' to the job; that does not solve the problem that there is an employer out there trying to take advantage of its employees. If you, as the employer, receive services from someone, the employee, you cannot expect to get them for free. That's a basic idea that our economies are founded on; so the proper thing would be for the employer to change its ways and that only comes about through discussion like ours.
There will always be someone for whom this is the only job he/she can find. If they "agree" to the terms it might be under the duress of overdue mortgages, rent, utilities bills, etc, similar to what Lovereading06 indicated.
There must be a labor law in the UK that would prevent such unfair treatment as you experienced. I'd be interested in hearing more about that.