I handed my CV today and there was no question about my age (and to be honest I look 14/15, rather than 16/17). So I'm assuming it was no issue.
And I sneakily gave it to the manager, not the cashiers (the advert said to hand it them), so I'm happy and he said he will get back to me... which means I know he got and he cannot ignore me (even if I don't get an interview!)
Now, I'm just waiting anxiously. Any guesses when they will get back to me? I'm going to say 10-15 days.