Ross Dress for Less review: customer service

The ross stores are close to my house, and there are a few items that I find convenient and cheap to get there, such as exercise clothes. But there is one store in particular where I almost always have a terrible experience, i'm surprised at myself for coming back there to shop. And today is no difference, but today is probably the last time they have me as a customer.
I bought a pair of slippers for a slipper drive at school. And when I was about to drop them off, I was shock to find that they were used slippers! But when I came to return them, the cashier didn't believe me. Not only that they sold me used goods, they doubted my integrity.
Another time I had an old sweater on coming out of the dressing room, and the attendant kept asking me whether that was my own sweater. I almost took it off to show her the label, which ross certainly doesnt sell, had she not been an elderly lady.
Anyway, i'm not sure why the store treats its customers like criminal suspect, but I will take my money and spend it elsewhere.
The store is ross on hawaii kai.