When I say this, please understand that I'm saying this as a person who would've wandered for 15 minutes as well -- but yeah, you COULD just ask someone who works there where the batteries are.
If it was Home Depot, he'd probably wander around for 45 minutes trying to find someone who works there.
It doesn't matter when I go there - mid-day, mid-week; or prime time, weekend. There's virtually no employees.
I usually end up going to the Customer Service desk and waiting 10 minutes while they summon someone on the radio/phone thingy.
Once the only person in the entire store was the lady at the self check-out aisles. And she couldn't help me because she wasn't allowed to leave her station because she was the only person in the store.
Try a different location if it's not much further away.