If this is in Australia I think you are being underpaid.
Check with wageline
\Now before you go off half cocked read the entire document.
Juniors usually get something like 50% of Adult rate
Shop Assistants in charge:
(i) without the duty of buying:
in charge of from nil to four assistants;
in charge of from five to twelve assistants;
Retail Food Employee working singly or in charge of one person
Retail Food Employee in charge of 2 or more persons
If you require assistance with any provisions of this pay scale please call Workplace Infoline on 1300 363 264