90210, you pose an interesting question.
You say the 'official hours' are 8-5 but this employee is expected to work from 7:30am to 6 pm each day. What do you mean by 'official hours'?
(a) those agreed with the employer when commencing the job?
(b) hours worked initially but which have now increased?
(c) the opening hours of this retailer?
The fact that this employee has been working these extended hours for some time, could be construed that they have accepted this change to their original terms of employment. However, the next bit is important.
Section 15 of the Organisation of Working Hours Act 1997 sets down the maximum working hours per week for employees (48) and from your posting, this employee appears to be working in excess of this.
Secondly, while this employer is not obliged to provide a contract in writing, the law (Terms of Employment Act 1994 and 2001) provides that certain aspects of their terms of employment must be provided in writing within 2 months of commencement. This means that details of their hours of work, rest periods, breaks must be provided to them in writing within 2 months of commencement of work. Again, it's an offence if this hasn't occurred.
Finally, work carried out on public holidays (forget the term 'bank holiday' as it's meaningless in law) give the employee an entitlement to time off in lieu. Work carried out over official working hours also attracts pay and employees have a right to this. Again, this doesn't seem to be happening in either of these instances - again an offence in law.
I could go on here - but basically the fact the employees are clocking-in and out means that this employer has largely hanged themselves. Since the hours worked are being recorded, the next step is easy.
I would recommend this employee gets in touch with the Employment Rights Unit at the Dept. Enterprise, Trade and Employment. They will put them in touch with the Labour Inspectorate who have a team of Inspectors. These Inspectors carry out random on-the-spot checks of employers to ensure compliance with the Organisation of Working Time (Records) Act 2001, etc. and to investigate breaches of employment rights in the workplace. The fact this employee has complained will not be revealed to the employer and the employer will be told it's a routine inspection. The extent of the breaches should then become obvious.
Option 2, is for this employee to take a case to the Labour Court. Option 3, is to speak to someone in your nearest Free Legal Advice Centre for free legal advice on what to do next.
I hope this has been of assistance.