First off you should ask your HR person where it is laid down in your terms and conditions of service that you are actually entitled to a meal break (not dinner hour) and if you are how the time for meal entitlement is accrued, normally a set number of minutes per rostered hours on the day. As has been mentioned before you may only be getting legally entitled SRATCOH breaks, which if you happen to eat during the break can not be designated a meal break.
