How to increase customers and increase profits?

I have a level 36 store, I have bakery, butcher and grocery departments and x1 vending machine. I get around 180 customers a day, but feel like i run out of cash really fast. Just restocking and having some supply in addition to shelf stock, means that most days I turn a small profit (1k), when I have to order for the butchery, or buy some additional licenses, minus wages, I often start the day with $100-500!!

All of my items are set at -1% off market price, I have apples on sale at 20% off. Which ive read increases customers. I have swapped out my double shelfs for single as I've read only 1 customer per shelf can shop. I have x3 registers and 2x self serve checkouts with a 29 shopper store capacity.

Most of the time, even with a 29 store capacity, the most people i've ever seen in store at once was 14...?

Any ideas??