This is not correct, you are entitled to a paid break without duties. This is an important entitlement that also relates to work, health and safety considerations. In some unforeseen circumstances, you can be called back from your break to perform duties such as supervising children, but you must be compensated for the missed time. In the modern award, it states that where an employee is called back to perform any duties within the centre or the break is interrupted for any reason, the employee will be paid 150% of the minimum hourly rate for a minimum of 15 minutes and thereafter to the nearest quarter hour until an uninterrupted break, or the balance of the break, is taken.
If you are under an enterprise agreement, check the conditions for meal breaks, it should cover circumstances where an employee has had to forego their meal break, and the employer should then reschedule the meal break as soon as possible.
Please contact your IEU Organiser if this situation does not get resolved.